System, data transmission method and network equipment supporting pdcp duplication function method and device for transferring supplementary uplink carrier configuration information and method and device for performing connection mobility adjustment

ABSTRACT

The present disclosure relates to a pre-5 th -Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4 th -Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure discloses a system, a data transmission method and a network equipment supporting a Packet Data Convergence Protocol (PDCP) duplication function. The data transmission method supporting a PDCP duplication function comprises the steps of: transmitting, by a first network equipment, a configuration instruction message of a radio bearer supporting a PDCP duplication function to a second network equipment; and, performing, by the first network equipment and the second network equipment, transmission of a data packet of the radio bearer configured with the PDCP duplication function. In the present disclosure, by an interface between the first network equipment and the second network equipment, the transmission of duplicated data packets between the first network equipment and the second network equipment is realized, and the reliability of data transmission is improved. The present disclosure also discloses a method and device for transferring supplementary uplink carrier configuration information and a method and device for performing a connection mobility adjustment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of International Application No.PCT/KR2018/005237 filed on May 4, 2018, which claims priority to ChinesePatent Application No. 201710316543.8 filed on May 5, 2017, ChinesePatent Application No. 201710461700.4 filed on Jun. 16, 2017, ChinesePatent Application No. 201810024386.8 filed on Jan. 10, 2018, andChinese Patent Application No. 201810028304.7 filed on Jan. 11, 2018,the disclosures of which are herein incorporated by reference in theirentirety.

BACKGROUND 1. Field

The present disclosure relates to the technical field of wirelesscommunication, and in particular to a system, a data transmission methodand a network equipment supporting a PDCP duplication function, a methodand device for transferring supplementary uplink carrier configurationinformation and a method and a device for performing a connectionmobility adjustment.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4^(th) generation (4G) communication systems, efforts havebeen made to develop an improved 5^(th) generation (5G) or pre-5Gcommunication system. Therefore, the 5G or pre-5G communication systemis also called a ‘Beyond 4G Network’ or a ‘Post Long Term Evolution(LTE) System’.

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud RadioAccess Networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul, moving network, cooperativecommunication, Coordinated Multi-Points (CoMP), reception-endinterference cancellation and the like.

In the 5G system, Hybrid frequency shift keying (FSK) and quadratureamplitude modulation (FQAM) and sliding window superposition coding(SWSC) as an advanced coding modulation (ACM), and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse codemultiple access (SCMA) as an advanced access technology have beendeveloped.

In a next-generation network or a 5G network, in order to supportnetwork function virtualization and to realize more efficient resourcemanagement and scheduling, a gNB providing a radio network interface fora UE can be further divided into a gNB Central Unit (gNB-CU) and a gNBDistributed Unit (gNB-DU). The gNB-CU has a Radio Resource Control (RRC)protocol layer, a Packet Data Convergence Protocol (PDCP) protocollayer, and optionally contains a Service Data Adaptation Protocol (SDAP)and the like. The gNB-DU has a Radio Link Control (RLC) protocol, aMedium Access Control (MAC) layer, a physical layer, and the like. Thereis a standardized public interface F1 between the gNB-CU and the gNB-DU.The F1 interface includes a control plane F1-C and a user plane F1-U. Atransmission network layer of the F1-C is transmitted based on InternetProtocol (IP). To realize a more reliable transmission signaling, aStream Control Transmission Protocol (SCTP) is additionally provided onthe basis of the IP. The protocol for an application layer is F1AP. TheSCTP can provide reliable message transmission in the application layer.A transport layer for the F1-U is UDP/IP, and the GTP-U on the UDP/IP isused for bearing Protocol Data Units (PDUs) of the user plane. FIG. 1shows the structures of the gNB-CU and the gNB-DU. In addition, in a newgeneration network, in order to improve the reliability of datatransmission or signaling transmission, the PDCP protocol layer willsupport a PDCP duplication function. This function is characterized inthat each PDCP PDU of a radio bearer supporting this function will betransmitted to at least two Radio Link Control (RLC) entities, thentransmitted to the MAC layer by two different logic channels oridentical logic channels and transmitted by two different cells,respectively. The radio bearer can be a Data Radio Bearer (DRB) or aSignaling Radio Bearer (SRB). This function can be applied in a carrieraggregation scenario and a dual-connectivity scenario.

In a carrier aggregation scenario, FIG. 2 shows a schematic diagram inwhich a transmitting terminal and a receiving terminal are included. Inthe transmitting terminal, a PDCP Service Data Unit (SDU) (which may bea data packet from the DRB or a data packet from the SRB) is processedby the PDCP protocol layer (including a PDCP duplication function) toobtain two identical PDCP PDUs (e.g., PDCP PDU1); and the two identicalPDCP PDUs will be transmitted to two different RLC entities (i.e., RLC 1and RLC 2), respectively, and then transmitted to the MAC layer throughtwo different logic channels (i.e., logic channel 1 and logic channel2), respectively. In the MAC layer, the data packets from the two logicchannels are transmitted by physical layers serving different cells(i.e., a cell 1 and a cell 2, where the two cells may employ differentcarriers or identical carriers). In the receiving terminal, data packetsfrom different carriers are processed by the MAC layer and thentransmitted to two different RLC entities (e.g., RLC1 and RLC2) throughdifferent logic channels, respectively; then, the RLC-processed datapackets are transmitted to the PDCP layer; and the PDCP layer willprocess duplicated PDCP PDUs (e.g., discard one of duplicated PDCP PDUs)to eventually obtain the PDCP SDU. In FIG. 2, the examples of thetransmitting terminal and the receiving terminal can be a gNB and a UE,or a UE and a gNB, or a UE and another UE, and the like.

In a dual-connectivity scenario, FIG. 3 shows a schematic diagram ofdownlink transmission (from a gNB to a UE). In the gNB, a PDCP SDU isprocessed by the PDCP protocol layer (containing a PDCP duplicationfunction) to obtain two identical PDCP PDUs (e.g., PDCP PDU1). The twoidentical PDCP PDUs will be transmitted to two different RLC entities ontwo different gNBs (i.e., gNB1 and gNB2), then transmitted to MAC layerscorresponding to the RLC entities respectively and eventuallytransmitted to user equipments through physical layers of two differentcells (i.e., a cell 1 and a cell 2, where the two cells may employdifferent carriers or identical carriers). On the user side, packetsreceived by the two different cells will be transmitted to two differentMAC entities and then transmitted to two different RLC entities; thedata packets output from the two RLC entities will be transmitted to asame PDCP entity; and the PDCP entity will process duplicated PDCP PDUs(e.g., discard a duplicated PDCP PDU) to eventually obtain a PDCP SDU.Similarly, FIG. 4a shows a schematic diagram of uplink transmission(from a UE to a gNB).

In addition, in a next-generation network or a fifth-generation (5G)network, a UE may also accept services from two base stations (a primarybase station and a secondary base station). The two base stations may betwo base stations of a same type, for example, base stations in 4G(eNBs) or base stations in 5G (gNBs); or the two base stations may bebase stations of different types, for example, an eNB and a gNB, or basestations of other types. In a case when the two base stations areserving an UE's radio bearer (e.g., a DRB or an SRB), the PDCP layerserving this radio bearer is located on one base station (e.g., a basestation 1, which may be the primary base station or the secondary basestation), and other protocol layers (e.g., an RLC layer, an MAC layerand a Physical Layer (PHY)) serving this radio bearer are located on theother base station (e.g., a base station 2, which may be the primarybase station or the secondary base station, wherein the base station 2is the secondary base station if the base station 1 is the primary basestation; and, the base station 2 is the primary base station if the basestation 1 is the secondary base station). Data of the radio bearer willbe transmitted on an interface (e.g., an X2 interface or an Xninterface) between the two base stations, as shown in FIG. 4 a.

In the description of the PDCP duplication function, the PDCP PDUsobtained after the PDCP duplication may belong to one radio bearer ormultiple radio bearers. The radio bearer can be a DRB for transmittingdata or an SRB for transmitting a signaling by a user. The radio bearersmay belong to one user or multiple users. It is indicated that only theuser is configured with a PDCP duplication function, if the radiobearers belong to one user; however, it is indicated that the multipleusers are configured with a PDCP duplication function, if the radiobearers belong to multiple different users.

In the description of the PDCP duplication function, one PDCP PDU istransmitted for two times by two different RLC entities. For thisfunction, it is also possible to transmit one PDCP PDU for multipletimes by multiple different RLC entities. In the subsequent descriptionof the present disclosure, transmitting one PDCP PDU for two times istaken as example. This also works in a situation where one PDCP PDU istransmitted for multiple times.

However, in a 5G system, a gNB may consist of two independent functionalentities, i.e., a gNB-CU and a gNB-DU, and an interface between thegNB-CU and the gNB-DU is standardized F1. In the conventional LTEnetwork, the gNB is one functional entity, and the interaction betweenall functions of this entity can be regarded as an internalimplementation. However, in 5G, how to realize transmission ofduplicated PDCP PDUs between the gNB-CU and the gNB-DU becomes a problemto be urgently solved at present, if one gNB consists of a gNB-CU and agNB-DU.

In the New Radio access (NR) network or 5G network, in order to improvethe uplink signal coverage, particularly at a high frequency, theconcept of Supplementary Uplink (SUL) carrier is proposed. For aFrequency Division Duplexing (FDD) system, usually one User Equipment(UE) is configured with one downlink carrier (or frequency/band) and oneuplink carrier (or frequency/band) (herein referred to as a non-SULcarrier). In order to improve the uplink coverage, the NR supports thatthe UE may be configured with another uplink carrier (orfrequency/band), which is the SUL carrier. Thus, one UE may beconfigured with two uplink carriers (one non-SUL carrier and one SULcarrier) and one downlink carrier, which belong to a same cell, as shownin FIG. 6. For a Time Division Duplexing (TDD) system, usually one UE isconfigured with one carrier where the UE performs uplink and downlinkcommunications in a time division manner. In order to improve the uplinkcoverage, the NR supports that the UE may be configured with anotheruplink carrier (or frequency/band), which is the SUL carrier. Thus, oneUE may be configured with one SUL carrier and one TDD carrier (hereinreferred to as a non-SUL carrier), which belong to a same cell, as shownin FIG. 7.

When an SUL carrier is introduced into a cell, one UE may transmit dataon two uplink carriers. However, under the control of the network, oneUE will not simultaneously transmit data in physical uplink sharedchannels (PUSCH) on the two uplink carriers. When the UE initiallyaccesses a cell that contains an SUL carrier, the UE may compare themeasured downlink signal strength of the cell with a threshold, and ifthe downlink signal strength is lower than the threshold, the UE mayperform a random access process on the SUL carrier to access the cell.

In order to support the SUL carrier, the NR system defines someconfiguration information related to the SUL carrier. A network sideentity may determine whether to configure the UE with an SUL carrieraccording to the channel state of the UE, or whether to schedule the UEto transmit data on an SUL carrier. However, currently the system mayneither exchange the SUL carrier configuration information betweenrelated network-side entities (e.g., between base stations, or between acentral unit and a distributed unit of a base station), noradd/modify/release an SUL carrier for UE between the network-sideentities. Thus, the network-side entities do not acquire respective cellconfiguration information and may not determine whether to configure theUE with a cell containing an SUL carrier, thereby triggering thenetwork-side entities to perform SUL carrier configuration. In addition,when a radio link failure occurs in the UE, the network-side entitiesmay not determine whether the failure is caused by using the SULcarrier, and then may not correct the SUL carrier parameterconfiguration for the failure caused by the SUL carrier, which affectsthe achievement of the purpose of introducing the SUL carrier to enhancethe uplink coverage. For this reason, it is necessary to provide amethod and device for transferring supplementary uplink carrierconfiguration information which may solve the above technical problem.

Modern mobile communications are increasingly tending to provide ahigher mobile bandwidth, less latency, and a support for a large numberof terminal services, which typically require supports forvirtualizations of network functions and a more efficient resourcemanagement and scheduling. For this reason, a base station (gNB) of anext-generation mobile communication system, such as a 5G mobilecommunication system, is divided into a central unit (gNB-CU) anddistributed unit(s) (gNB-DU(s)), instead of a base station (eNB) in aconventional LTE network which can be considered as a single functionalentity. The connection mobility adjustment performed by the base stationis no longer an internal implementation of a single functional entitydue to the separation between the gNB-DU(s) and the gNB-CU, and thus themechanism in the eNB is not applicable any more. Currently there is nospecification on how to implement a connection mobility adjustment in agNB.

Therefore, there is a need for a new mechanism for performing aconnection mobility adjustment in a gNB.

SUMMARY

The present disclosure provides a system, a data transmission method anda network equipment supporting a PDCP duplication function in order torealize the transmission of duplicated data packets between a firstnetwork equipment and a second network equipment and to improve thereliability of data transmission; another objective of the presentdisclosure is to overcome the shortage of the prior art by providing amethod and device for transferring supplementary uplink carrierconfiguration information, which may effectively enhance the uplinkcoverage of the NR system; another objective of the present disclosureis to provide a mechanism for performing a connection mobility parameteradjustment by the cooperation among the central unit and the distributedunits of the base station.

A first network equipment is provided, including: a transmitting subunitconfigured to transmit, to a second network equipment, a configurationinstruction message of a radio bearer supporting a Packet DataConvergence Protocol (PDCP) duplication function; and a processingsubunit configured to perform, with the second network equipment,transmission of a data packet of the radio bearer configured with thePDCP duplication function.

When the data packet of the radio bearer configured with the PDCPduplication function is downlink data,

the transmitting subunit is configured to transmit, by an interfacebetween the first network equipment and the second network equipment,the data packet of the radio bearer configured with the PDCP duplicationfunction.

When the first network equipment and the second network equipmentactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the transmitting subunit is specificallyconfigured to transmit, by a tunnel on the interface between the firstnetwork equipment and the second network equipment, the data packet ofthe radio bearer configured with the PDCP duplication function to thesecond network equipment; or

the transmitting subunit is specifically configured to duplicate thedata packet of the radio bearer configured with the PDCP duplicationfunction to obtain two identical data packets of the radio bearerconfigured with the PDCP duplication function, and transmit, by a tunnelon the interface between the first network equipment and the secondnetwork equipment, the two identical data packets of the radio bearerconfigured with the PDCP duplication function, respectively; or,specifically configured to transmit, by a tunnel on the interfacebetween the first network equipment and the second network equipment,the data packet of the radio bearer configured with the PDCP duplicationfunction for two times; or

the transmitting subunit is specifically configured to transmit, by twodifferent tunnels on the interface between the first network equipmentand the second network equipment, the data packet of the radio bearerconfigured with the PDCP duplication function to the second networkequipment for two times; or

the transmitting subunit is specifically configured to transmit, by acontrol plane message on the interface between the first networkequipment and the second network equipment, two identical data packetsof the radio bearer configured with the PDCP duplication function to thesecond network equipment.

When the first network equipment does not activate the PDCP duplicationfunction of the radio bearer supporting the PDCP duplication function,the transmitting subunit is specifically configured to transmit, via theinterface between the first network equipment and the second networkequipment, the data packet of the radio bearer configured with the PDCPduplication function to the second network equipment so that the secondnetwork equipment transmits, successively via a specified orself-selected RLC entity and a corresponding logic channel thereof, anMAC layer and a cell, the data packet to a user terminal.

When the transmitting subunit transmits the data packet of the radiobearer configured with the PDCP duplication function to the secondnetwork equipment, the transmission is realized by a tunnel on theinterface between the first network equipment and the second networkequipment or a control plane message on the interface between the firstnetwork equipment and the second network equipment; and when thetransmitting subunit transmits the data packet of the radio bearerconfigured with the PDCP duplication function to the second networkequipment, one tunnel on the interface between the first networkequipment and the second network equipment includes a specified tunnelor a self-selected tunnel.

When the data packet of the radio bearer configured with the PDCPduplication function is uplink data, the first network equipment furtherincludes:

a receiving subunit configured to receive the data packet of the radiobearer configured with the PDCP duplication function transmitted by thesecond network equipment; and

the processing subunit is configured to process, by a PDCP layer, thereceived data packet of the radio bearer configured with the PDCPduplication function to obtain a PDCP Service Data Unit (SDU) of theradio bearer configured with the PDCP duplication function.

The configuration instruction message of the radio bearer supporting thePDCP duplication function transmitted to the second network equipment bythe transmitting subunit includes at least one of the followinginformation:

information indicating the support of the PDCP duplication function;

part or all of configuration information of at least one Radio LinkControl protocol (RLC) entity corresponding to a data bearer;

identifier information and/or configuration information of a logicchannel corresponding to at least one RLC entity;

configuration information of at least one tunnel on the interfacebetween the first network equipment and the second network equipment;

information about a correspondence between at least one tunnel on theinterface between the first network equipment and the second networkequipment and at least one RLC entity; and indication information foridentifying a duplicated data packet.

The first network equipment further includes:

a receiving subunit configured to receive a configuration responsemessage returned by the second network equipment, wherein theconfiguration response message includes configuration information of atleast one tunnel on the interface between the first network equipmentand the second network equipment.

The configuration information of at least one tunnel on the interfacebetween the first network equipment and the second network equipmentcontained in the configuration instruction message is specificallyaddress information for receiving or transmitting, by the first networkequipment, the data packet of the radio bearer supporting the PDCPduplication function; and, the configuration information of at least onetunnel on the interface between the first network equipment and thesecond network equipment contained in the configuration response messageis specifically address information for receiving or transmitting, onthe second network equipment side, the data packet of the radio bearersupporting the PDCP duplication function.

Preferably, the first network equipment is a first base station, and thesecond network equipment is a second base station; or

the first network equipment is a Central Unit (CU) in a base station,and the second network equipment is a Distributed Unit (DU) in the basestation.

The present disclosure further provides a second network equipment,including:

a receiving subunit configured to receive a configuration instructionmessage of a radio bearer supporting a PDCP duplication functiontransmitted by a first network equipment; and

a processing subunit configured to perform, with the first networkequipment, transmission of a data packet of the radio bearer configuredwith the PDCP duplication function.

When the data packet of the radio bearer configured with the PDCPduplication function is downlink data, the second network equipmentfurther includes:

the receiving subunit configured to receive, by an interface between thesecond network equipment and the first network equipment, the datapacket of the radio bearer configured with the PDCP duplicationfunction; and

a transmitting subunit configured to transmit the data packet of theradio bearer configured with the PDCP duplication function to twodifferent cells, respectively.

When the first network equipment and the second network equipmentactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the receiving subunit is configured toreceive, by a tunnel on the interface between the second networkequipment and the first network equipment, the data packet of the radiobearer configured with the PDCP duplication function transmitted by thefirst network equipment;

the processing subunit is specifically configured to duplicate the datapacket of the radio bearer configured with the PDCP duplication functionto obtain two identical data packets of the radio bearer configured withthe PDCP duplication function; and

the transmitting subunit is specifically configured to transmit, by twodifferent RLC entities and corresponding logic channels and via an MAClayer, the two identical data packets of the radio bearer configuredwith the PDCP duplication function to two different cells, respectively.

When the first network equipment and the second network equipmentactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the receiving subunit is configured toreceive, by a tunnel on the interface between the second networkequipment and the first network equipment, the data packet of the radiobearer configured with the PDCP duplication function transmitted by thefirst network equipment; and

the transmitting subunit is specifically configured to transmit, by twodifferent RLC entities and corresponding logic channels and via an MAClayer, the data packet of the radio bearer configured with the PDCPduplication function to two different cells once, respectively.

When the first network equipment and the second network equipmentactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the receiving subunit is configured toreceive, by one or two tunnels on the interface between the secondnetwork equipment and the first network equipment and for two times, twoidentical data packets of the radio bearer configured with the PDCPduplication function transmitted by the first network equipment; and thetransmitting subunit is specifically configured to transmit, by twodifferent RLC entities and corresponding logic channels and via an MAClayer, two identical data packets of the radio bearer configured withthe PDCP duplication function to two different cells, respectively.

When the first network equipment and the second network equipmentactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the receiving subunit is configured toreceive, by a control plane message on the interface between the secondnetwork equipment and the first network equipment and via receptions oftwo times, two identical data packets of the radio bearer configuredwith the PDCP duplication function transmitted by the first networkequipment; and the transmitting subunit is specifically configured totransmit, by two different RLC entities and corresponding logic channelsand via an MAC layer, two identical data packets of the radio bearerconfigured with the PDCP duplication function to two different cells,respectively.

When the first network equipment and the second network equipment do notactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the receiving subunit is specificallyconfigured to receive the data packet of the radio bearer configuredwith the PDCP duplication function transmitted by the first networkequipment via the interface between the second network equipment and thefirst network equipment; and the transmitting subunit is specificallyconfigured to transmit, successively via a specified or self-selectedRLC entity and a corresponding logic channel thereof, an MAC layer and acell, the data packet of the radio bearer configured with the PDCPduplication function to a user terminal.

When the data packet of the radio bearer configured with the PDCPduplication function is uplink data, the second network equipmentfurther includes:

a transmitting subunit configured to transmit the data packet of theradio bearer configured with the PDCP duplication function to the firstnetwork equipment.

When the first network equipment and the second network equipmentactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the transmitting subunit is specificallyconfigured to transmit, by one or two tunnels on the interface betweenthe second network equipment and the first network equipment or acontrol plane message on the interface between the second networkequipment and the first network equipment, two identical data packets ofthe radio bearer configured with the PDCP duplication function acquiredfrom two different cells to the first network equipment, the twoidentical data packets being obtained via physical layers of the cells,MAC layers, two different logic channels and corresponding RLC entitiesthereof.

When the first network equipment and the second network equipment do notactivate the PDCP duplication function of the radio bearer supportingthe PDCP duplication function, the transmitting subunit is specificallyconfigured to transmit, via the interface between the second networkequipment and the first network equipment and to the first networkequipment, the data packet of the radio bearer configured with the PDCPduplication function acquired from a cell, the data packet beingobtained via a physical layer of the cell, an MAC layer, a logic channeland a corresponding RLC entity thereof.

The second network equipment transmits, by a tunnel on the interfacebetween the second network equipment and the first network equipment ora control plane message on the interface between the second networkequipment or the first network equipment and to the first networkequipment, the data packet of the radio bearer configured with the PDCPduplication function acquired from a cell, the data packet beingobtained via a physical layer of the cell, an MAC layer, a logic channeland a corresponding RLC entity thereof.

One tunnel on the interface between the second network equipment and thefirst network equipment includes a specified tunnel or a self-selectedtunnel, and the RLC entity includes a specified RLC entity or aself-selected RLC entity.

The second network equipment further includes:

a transmitting subunit configured to transmit, to the first networkequipment, a configuration response message carrying configurationinformation of at least one tunnel on the interface between the secondnetwork equipment and the first network equipment.

The configuration information of at least one tunnel on the interfacebetween the second network equipment and the first network equipmentcontained in the configuration response message is specifically addressinformation for receiving by the receiving subunit or transmitting bythe transmitting subunit the data packet of the radio bearer configuredwith the PDCP duplication function.

Preferably, the first network equipment is a first base station, and thesecond network equipment is a second base station; or the first networkequipment is a Central Unit (CU) in a base station, and the secondnetwork equipment is a Distributed Unit (DU) in the base station.

The present disclosure discloses a system supporting a Packet DataConvergence Protocol (PDCP) duplication function, including the firstbase station and the second base station or the CU and the DU in thebase station described above; and the data of the radio bearerconfigured with the PDCP duplication function includes: a data packet ofa data radio bearer configured with a PDCP duplication function and/or adata packet of a signaling radio bearer configured with a PDCPduplication function.

The present disclosure discloses a data transmission method supporting aPDCP duplication function, including the steps of:

transmitting, by a first network equipment and to a second networkequipment, a configuration instruction message of a radio bearersupporting a PDCP duplication function; and performing, by the firstnetwork equipment and with the second network equipment, transmission ofa data packet of the radio bearer configured with the PDCP duplicationfunction.

Preferably, the first network equipment is a first base station, and thesecond network equipment is a second base station; or the first networkequipment is a Central Unit (CU) in a base station, and the secondnetwork equipment is a Distributed Unit (DU) in the base station.

Compared with the prior art, the present disclosure has at least thefollowing advantages: by an interface between a first network equipmentand a second network equipment, the transmission of duplicated datapackets between the first network equipment and the second networkequipment is realized, and the reliability of data transmission isimproved.

The present disclosure provides a method for transferring resourceconfiguration information, including steps of:

acquiring, by a first network-side entity, Supplementary Uplink (SUL)carrier configuration information; and

sending, by the first network-side entity, a configuration messagecarrying the SUL carrier configuration information to a secondnetwork-side entity.

Preferably, the SUL carrier configuration information includes at leastone of: SUL carrier configuration information of at least one first cellserved by the first network-side entity;

SUL carrier configuration information of at least one first neighboringcell of a cell served by the first network-side entity;

SUL carrier configuration information of at least one second cell servedby other base station;

SUL carrier configuration information of at least one second neighboringcell of a cell served by the other base station; and

SUL carrier configuration information of at least one first cell servinga User Equipment (UE), the first cell being served by the firstnetwork-side entity, and the UE being served by the first network-sideentity.

Preferably, the configuration message further includes at least one of:indication information related to an uplink carrier of a UE;

indication information related to a modification of an uplink carrierconfiguration of the UE;

indication information indicating to configure random access-relatedinformation on an SUL carrier for the UE;

indication information indicating to modify the random access-relatedinformation on the SUL carrier for the UE;

indication information indicating that the SUL carrier is supported byat least one first cell served by the first network-side entity;

indication information indicating that the SUL carrier is supported byat least one first neighboring cell of a cell served by the firstnetwork-side entity;

indication information indicating that the SUL carrier is supported byat least one second cell served by other base station; and

indication information indicating that the SUL carrier is supported byat least one second neighboring cell of a cell served by the other basestation.

Preferably, before acquiring, by the first network-side entity,Supplementary Uplink (SUL) carrier configuration information, the methodfurther includes:

receiving, by the first network-side entity, a request message sent bythe second network-side entity for acquiring the SUL carrierconfiguration information, the request message carrying the SUL carrierconfiguration information acquired by the second network-side entity.

Preferably, the SUL carrier configuration information acquired by thesecond network-side entity includes at least one of: SUL carrierconfiguration information of at least one first cell served by thesecond network-side entity;

SUL carrier configuration information of at least one first neighboringcell of a cell served by the second network-side entity;

SUL carrier configuration information of at least one second cell servedby other base station; and

SUL carrier configuration information of at least one second neighboringcell of a cell served by the other base station.

Preferably, the request message further carries at least one of:

indication information related to an uplink carrier of a UE;

indication information related to a modification of an uplink carrierconfiguration of the UE;

indication information indicating to configure random access-relatedinformation on an SUL carrier for the UE;

indication information indicating to modify the random access-relatedinformation on the SUL carrier for the UE;

indication information indicating that the SUL carrier is supported byat least one first cell served by the second network-side entity;

indication information indicating that the SUL carrier is supported byat least one first neighboring cell of a cell served by the secondnetwork-side entity;

indication information indicating that the SUL carrier is supported byat least one first cell served by other base station;

indication information indicating that the SUL carrier is supported byat least one second neighboring cell of a cell served by the other basestation; and

information related to a cell measurement result.

Preferably, after receiving, by the first network-side entity, a requestmessage sent by the second network-side entity for acquiring the SULcarrier configuration information, the method further includes:

if the request message carries indication information related to anuplink carrier of a UE, the first network-side entity judges whether totransmit the SUL carrier configuration information to the secondnetwork-side entity according to the indication information related tothe uplink carrier of the UE; and

if so, performing the step of acquiring, by the first network-sideentity, Supplementary Uplink (SUL) carrier configuration information.

Preferably, the indication information related to the uplink carrier ofthe UE includes at least one of:

indication information indicating to configure a non-SupplementaryUplink (non-SUL) carrier for a UE;

indication information indicating to configure an SUL carrier for theUE; and

indication information indicating to configure a non-SUL carrier and anSUL carrier for the UE.

Preferably, after sending, by the first network-side entity, theconfiguration message carrying the SUL carrier configuration informationto the second network-side entity, the method further includes:

receiving, by the first network-side entity, an acknowledge message sentby the second network-side entity, the acknowledge message comprising atleast one of:

SUL carrier configuration information of at least one first cell servedby the second network-side entity;

SUL carrier configuration information of at least one first neighboringcell of a cell served by the second network-side entity;

SUL carrier configuration information of at least one second cell servedby other base station;

SUL carrier configuration information of at least one second neighboringcell of a cell served by the other base station;

indication information indicating that an SUL carrier is supported by atleast one first cell served by the second network-side entity;

indication information indicating that the SUL carrier is supported byat least one first neighboring cell of a cell served by the secondnetwork-side entity;

indication information indicating that the SUL carrier is supported byat least one second cell served by other base station; and

indication information indicating that the SUL carrier is supported byat least one second neighboring cell of a cell served by the other basestation.

Preferably, the SUL carrier configuration information includes at leastone of:

identification information of a cell where an SUL carrier is located;

identification information of a base station locating the cell where theSUL carrier is located;

a carrier frequency of the SUL carrier;

a bandwidth of the SUL carrier;

an initial uplink bandwidth portion of the SUL carrier;

signal strength threshold information of the SUL carrier;

configuration information related to a random access on the SUL carrier;

configuration information of a Physical Uplink Control Channel (PUCCH)on the SUL carrier;

configuration information of a Physical Uplink Shared Channel (PUSCH) onthe SUL carrier; and

configuration information of a Sounding Reference Signal, SRS, on theSUL carrier.

Preferably, the first network-side entity includes a first base station,and the second network-side entity includes a second base station; orthe first network-side entity includes a distributed unit of the firstbase station, and the second network-side entity includes a central unitof the first base station.

In order to achieve the above objective, the present disclosure furtherprovides a network-side device, including:

an SUL carrier configuration information acquiring module configured toacquire SUL carrier configuration information; and

an SUL carrier configuration information transmitting module configuredto transmit a configuration message carrying the SUL carrierconfiguration information to a network-side entity.

In order to achieve the above objective, the present disclosure furtherprovides a method for transferring configuration optimizationinformation, including steps of:

acquiring, by a first network-side entity, link failure-relatedinformation of a User Equipment (UE); and

optimizing, by the first network-side entity, configuration parametersof the UE severed by the first network-side entity according to the linkfailure-related information.

Preferably, acquiring, by the first network-side entity, linkfailure-related information of the User Equipment (UE) includes:

receiving, by the first network-side entity, a message sent by the UE toacquire the link failure-related information of the UE; or

receiving, by the first network-side entity, the link failure-relatedinformation of the UE sent by a second network-side entity.

Preferably, the link failure-related information of the UE sent by thesecond network-side entity is sent from a third network-side entity tothe second network-side entity; or, the link failure-related informationof the UE is received by the third network-side entity from the UE, andthen forwarded to the second network-side entity; or the linkfailure-related information of the UE is sent to the second network-sideentity by the UE.

Preferably, the link failure-related information includes at least oneof:

cause information of a link failure of the UE; and information relatedto a use of a Supplementary Uplink (SUL) carrier by the UE.

Preferably, the first network-side entity includes a base station, and acentral unit of the base station or a distributed unit of the basestation; the second network-side entity includes a base station, and acentral unit of the base station or a distributed unit of the basestation; the third network-side entity comprises a base station, and acentral unit of the base station or a distributed unit of the basestation.

In order to achieve the above objective, the present disclosure furtherprovides a network-side device, including:

a link failure information acquiring module configured to acquire linkfailure-related information of a User Equipment (UE); and

an optimization module configured to optimize configuration parametersof the served UE according to the link failure-related information.

In order to achieve the above objective, the present disclosure furtherprovides a method for transferring configuration optimizationinformation, including steps of:

acquiring, by a User Equipment (UE) link failure-related information;and

transmitting, by the UE, the link failure-related information to anetwork-side entity.

Preferably, the link failure-related information includes at least oneof:

cause information of a link failure of the UE;

information related to a use of a Supplementary Uplink (SUL) carrier bythe UE.

In order to achieve the above objective, the present disclosure furtherprovides a user equipment, including:

a link failure information acquiring module configured to acquire linkfailure-related information; and

a link failure information transmitting module configured to transmitthe link failure-related information to a network-side entity.

As compared with the prior art, the technical effects of the presentdisclosure include, but are not limited to: by transferring andexchanging the SUL carrier configuration information between thenetwork-side entities, the present disclosure helps a base station (or acentral unit of a base station) acquires an SUL carrier configuration ofother base station (or a distributed unit of a base station), so that anetwork-side entity may determine whether to configure a cell containingthe SUL carrier for the UE, thereby fully utilizing the SUL carrier toexpand the system uplink coverage

According to the disclosure, a method performed in a central unit of abase station is provided. The method includes: transmitting a connectionmobility adjustment request message to the distributed unit of the basestation; and receiving a connection mobility adjustment acknowledgementmessage from the distributed unit of the base station.

According to the disclosure, a central unit of a base station isprovided. The central unit includes: a transmitting module configured totransmit a connection mobility adjustment request message to thedistributed unit of the base station; and a receiving module configuredto receive a connection mobility adjustment acknowledgement message fromthe distributed unit of the base station.

According to the disclosure, a method performed in a distributed unit ofa base station is provided, which including: receiving a connectionmobility adjustment request message from a central unit of the basestation; and transmitting, in response to the received connectionmobility adjustment request message, a connection mobility adjustmentacknowledgement message to the central unit of the base station.

According to the disclosure, a distributed unit of a base station isprovided. The distributed unit includes: a receiving module configuredto receive a connection mobility adjustment request message from acentral unit of the base station; and a transmitting module configuredto transmit, in response to the received connection mobility adjustmentrequest message, a connection mobility adjustment acknowledgementmessage to the central unit of the base station.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structure diagram of a gNB-CU and a gNB-DU in theprior art;

FIG. 2 is a schematic flowchart of PDCP duplication in a carrieraggregation scenario in the prior art;

FIG. 3 is a schematic flowchart of PDCP duplication in a downlinkdual-connectivity scenario in the prior art;

FIG. 4a is a schematic flowchart of PDCP duplication in an uplinkdual-connectivity scenario in the prior art;

FIG. 4b is a schematic flowchart of PDCP duplication in atwo-base-station scenario in the prior art; and

FIG. 5 is a schematic flowchart of a data transmission method supportinga PDCP duplication function on the first network equipment sideaccording to the present disclosure.

FIG. 6 is a schematic diagram of a supplementary uplink carrier in anFDD system;

FIG. 7 is a schematic diagram of a supplementary uplink carrier in a TDDsystem;

FIG. 8 is a flowchart of a supplemental uplink carrier configurationmethod according to the present disclosure;

FIG. 9 is a schematic diagram of exchanging SUL carrier configurationinformation between two base stations according to Embodiment of thepresent disclosure;

FIG. 10 is a schematic diagram of exchanging SUL carrier configurationinformation between a central unit and a distributed unit of a basestation according to Embodiment of the present disclosure;

FIG. 11 is a schematic diagram of an addition/modification/release of anSUL carrier decided by a central unit of a base station according toEmbodiment of the present disclosure;

FIG. 12 is a schematic diagram of a selection of an SUL carrier by a UEfor a random access according to Embodiment of the present disclosure;

FIG. 13 is a schematic diagram of an addition/modification/release of anSUL carrier decided by a distributed unit of a base station (assisted bya central unit) according to Embodiment of the present disclosure;

FIG. 14 is a schematic diagram of an addition/modification/release of anSUL carrier decided by a distributed unit of a base station according toEmbodiment of the present disclosure;

FIG. 15 is a schematic diagram of a radio link failure mode of a UEaccording to Embodiment of the present disclosure;

FIG. 16 is a schematic diagram of another radio link failure mode of aUE according to Embodiment of the present disclosure;

FIG. 17 is a schematic diagram where a UE reports a link failure reportto a network side according to Embodiment of the present disclosure;

FIG. 18 is a schematic diagram where a distributed unit of a basestation reports a link failure report to a central unit according toEmbodiment of the present disclosure; and

FIG. 19 is a module block diagram of a network-side device for asupplemental uplink carrier configuration method according to thepresent disclosure.

FIG. 20 schematically shows a system architecture diagram of an exampleof a next generation mobile communication system;

FIG. 21 schematically shows a structural diagram of an example of a basestation of a next generation mobile communication system;

FIGS. 22A and 22B schematically show a schematic diagram of a method forperforming a connection mobility adjustment according to a firstembodiment of the present disclosure;

FIGS. 23A and 23B schematically show a schematic diagram of a method forperforming a connection mobility adjustment according to a secondembodiment of the present disclosure;

FIGS. 24A and 24B schematically show a schematic diagram of a method forperforming a connection mobility adjustment according to a thirdembodiment of the present disclosure;

FIGS. 25A and 25B schematically illustrate a schematic diagram of amethod for performing a connection mobility adjustment according to afourth embodiment of the present disclosure;

FIGS. 26A and 26B schematically illustrate a schematic diagram of amethod for performing a connection mobility adjustment according to afifth embodiment of the present disclosure;

FIG. 27 schematically illustrates a schematic diagram of a method forperforming a connection mobility adjustment according to a sixthembodiment of the present disclosure;

FIG. 28 schematically illustrates a schematic diagram of a method forperforming a connection mobility adjustment according to a secondembodiment of the present disclosure;

FIG. 29 schematically shows a block diagram of a structural example of acentral unit of a base station according to an embodiment of the presentdisclosure;

FIG. 30 schematically shows a block diagram of a structural example of adistributed unit of a base station according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION

The present disclosure provides a system, a data transmission method anda network equipment supporting a PDCP duplication function, a method anddevice for transferring supplementary uplink carrier configurationinformation, and a method and a device for performing a connectionmobility adjustment. Specific implementations of the present disclosurewill be described below in detail with reference to the accompanyingdrawings.

Embodiments of the present disclosure will be described in detailhereinafter. The examples of these embodiments have been illustrated inthe accompanying drawings throughout which same or similar referencenumerals refer to same or similar elements or elements having same orsimilar functions. The embodiments described with reference to theaccompanying drawings are illustrative, merely used for explaining thepresent disclosure and should not be regarded as any limitationsthereto.

It should be understood by one person of ordinary skill in the art thatsingular forms “a”, “an”, “the”, and “said” may be intended to includeplural forms as well, unless otherwise stated. It should be furtherunderstood that terms “comprise/comprising” used in this specificationspecify the presence of the stated features, integers, steps,operations, elements and/or components, but not exclusive of thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or combinations thereof. It shouldbe understood that, when a component is referred to as being “connectedto” or “coupled to” another component, it can be directly connected orcoupled to other elements or provided with intervening elementstherebetween. In addition, “connected to” or “coupled to” as used hereincan comprise wireless connection or coupling. As used herein, the term“and/or” comprises all or any of one or more associated listed items orcombinations thereof.

It should be understood by one person of ordinary skill in the art that,unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneperson of ordinary skill in the art to which the present disclosurebelongs. It should be further understood that terms, such as thosedefined in commonly used dictionaries, should be interpreted as having ameaning that is consistent with their meanings in the context of theprior art and will not be interpreted in an idealized or overly formalmeaning unless expressly so defined herein.

It may be understood by those skilled in the art that the “terminal” and“user equipment” used herein include not only the radio signal receiverdevice which only has a radio signal receiver without any transmittingcapability, but also the receiving and transmitting hardware devicewhich is capable of reception and transmission in a two-waycommunication over a two-way communication link. Those devices mayinclude a cellular or other communication device with a single-linedisplay or a multi-line display or without any multi-line display; aPersonal Communications Service (PCS) capable of combining voice, dataprocessing, fax and/or data communication capabilities; a PersonalDigital Assistant (PDA) which may include a radio receiver, a pager, anInternet/intranet access, a web browser, a notepad, calendar, and/or aGlobal Positioning System (GPS) receiver; a conventional laptop and/or apalmtop computer or other device having and/or including a radiofrequency receiver. The “terminal” and “terminal device” used herein maybe portable, transportable and mounted in a vehicle (aviation, marine,and/or land), or suitable and/or configured to run locally, and/or runat any other location on the earth and/or in the space in a distributedmanner. The “terminal” and “terminal device” used herein may also be acommunication terminal, an Internet terminal, a music/video playingterminal (e.g., PDA, Mobile Internet Device (MID)) and/or a mobile phonewith a music/video playing function, a smart television, a set-top box,etc.

The base station involved in the present disclosure may be a basestation of a NR system (gNB), a base station of an LTE system (eNB), orany other type of base station. An interface between base stations is anX2 interface or an Xn interface, or any other interface. In addition,one base station may include a central unit (CU) and a distributed unit(DU). The CU at least has a Radio Resource Control (RRC) layer and aPacket Data Convergence Protocol (PDCP) layer and the like, and may alsoinclude a Service Data Adaptation Protocol (SDAP) layer. The DU has aRadio Link Control (RLC) protocol layer, a Medium Access Control (MAC)layer, a physical layer, and the like. Between the CU and DU is astandardized public interface F1, or any other interface.

The name of any message mentioned in the present disclosure is just anexample, and other name may also be used.

In the system supporting a PDCP duplication function provided by thepresent disclosure, a base station can be a gNB in a new generationnetwork, including a gNB-CU and a gNB-DU; or, the base station can be abase station in other networks (e.g., an eNB in an LTE system). Tofacilitate understanding, the following embodiments 1 to 5 will bedescribed by taking a base station supporting a PDCP duplicationfunction as example, including a central unit and a distributed unit. Inthe Embodiments 1 to 5, a gNB-CU (a first network equipment) and agNB-DU (a second network equipment) are taken as example; however, thecentral unit and the distributed unit included in the base station inother networks are also applicable to the present disclosure.

To facilitate understanding, the method for transmitting, between acentral unit and a distributed unit, a data packet of a radio bearersupporting a PDCP duplication function in the present disclosure will bespecifically described in the following embodiments of the presentdisclosure by using a PDCP PDU as the data packet. Of course, in anactual system, the format of the data packet is not limited thereto.

The PDCP duplication function mentioned in the present disclosure willbe described by taking the data packet of the radio bearer supportingthe PDCP duplication function being transmitted for two times asexample. However, in an actual system, the data packet can betransmitted for multiple times. In this case, the data packet of theradio bearer can be transmitted within multiple cells by multiple RLCentities and corresponding channels thereof, and can be transmitted byone or more tunnels on an F1 interface. In the following embodiments 1to 5 of the present disclosure, for convenience, the detail descriptionwill be given by taking the data packet being transmitted for two timesas example.

In the present disclosure, a tunnel is used for transmitting data of auser plane.

The base station supporting a PDCP duplication function includes aCentral Unit (CU) and a Distributed Unit (DU).

The CU is configured to:

transmit, to the DU, a configuration instruction message of a radiobearer supporting a PDCP duplication function, wherein the configurationinstruction message of the radio bearer supporting the PDCP duplicationfunction transmitted to the DU by the CU includes at least one of thefollowing information:

information indicating the support of the PDCP duplication function;

part or all of configuration information of at least one RLC entitycorresponding to a data bearer;

identifier information and/or configuration information of a logicchannel corresponding to at least one RLC entity;

configuration information of at least one tunnel on the F1 interface;

information about a correspondence between at least one tunnel on the F1interface and at least one RLC entity; and

indication information for identifying a duplicated data packet.

Further, the CU is further configured to receive a configurationresponse message returned by the DU, wherein the configuration responsemessage includes configuration information of at least one tunnel on theF1 interface; and, the configuration message contains addressinformation of the tunnel, which can be one or two pieces of addressinformation.

The CU is further configured to perform, with the DU, transmission of adata packet of the radio bearer configured with the PDCP duplicationfunction.

The DU is configured to: receive a configuration instruction message ofa radio bearer supporting a PDCP duplication function transmitted by theCU; transmit, to the CU, a configuration response message carryingconfiguration information of at least one tunnel on an F1 interface, theconfiguration information containing address information of the tunnel,which can be one or two pieces of address information; and, perform,with the CU, transmission of a data packet of the radio bearerconfigured with the PDCP duplication function.

The configuration information of at least one tunnel on the F1 interfacecontained in the configuration instruction message of the radio bearersupporting the PDCP duplication function transmitted to the DU by the CUis specifically address information for receiving or transmitting, bythe CU, the data packet of the radio bearer supporting the PDCPduplication function; and, the configuration information of at least onetunnel on the F1 interface contained in the received configurationresponse message retuned by the DU is specifically address informationfor receiving or transmitting, on the DU side, the data packet of theradio bearer supporting the PDCP duplication function.

The data packet of the radio bearer configured with the PDCP duplicationfunction includes: a data packet of a data radio bearer configured witha PDCP duplication function and/or a data packet of a signaling radiobearer configured with a PDCP duplication function.

The transmission of the data packet of the radio bearer configured withthe PDCP duplication function between the CU and the DU will bespecifically described for two situations, i.e., a situation where thedata packet of the radio bearer configured with the PDCP duplicationfunction is uplink data and a situation where the data packet of theradio bearer configured with the PDCP duplication function is downlinkdata.

When the data packet of the radio bearer configured with the PDCPduplication function is downlink data, the CU is configured to transmit,by an F1 interface between the CU and the DU, the data packet of theradio bearer configured with the PDCP duplication function; and

the DU is configured to transmit the data packet of the radio bearerconfigured with the PDCP duplication function to two different cells,respectively.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the CU isspecifically configured to transmit, by a tunnel on the F1 interface,the data packet of the radio bearer configured with the PDCP duplicationfunction to the DU; and the DU is specifically configured to duplicatethe data packet of the radio bearer configured with the PDCP duplicationfunction to obtain two identical data packets of the radio bearerconfigured with the PDCP duplication function, and transmit, by twodifferent RLC entities and corresponding logic channels thereof and viaan MAC layer, the two identical data packets of the radio bearerconfigured with the PDCP duplication function to two different cells,respectively. Or, the DU is specifically configured to transmit, by twodifferent RLC entities and corresponding logic channels and via an MAClayer, the data packet of the radio bearer configured with the PDCPduplication function to two different cells once, respectively.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the CU isspecifically configured to duplicate the data packet of the radio bearerconfigured with the PDCP duplication function to obtain two identicaldata packets of the radio bearer configured with the PDCP duplicationfunction, and transmit, by a tunnel on the F1 interface, the twoidentical data packets of the radio bearer configured with the PDCPduplication function to the DU, respectively; or, specificallyconfigured to transmit, by a tunnel on the F1 interface, the data packetof the radio bearer configured with the PDCP duplication function to theDU for two times; and the DU is specifically configured to transmit, bytwo different RLC entities and corresponding logic channels and via anMAC layer, two identical data packets of the radio bearer configuredwith the PDCP duplication function to two different cells, respectively.

When the CU and the DU activate the PDCP duplication function of theradio bearer configured with the PDCP duplication function, the CU isspecifically configured to transmit, by two different tunnels on the F1interface, two identical data packets of the radio bearer configuredwith the PDCP duplication function to the DU, respectively; or,transmit, by a control plane message on the F1 interface, two identicaldata packets of the radio bearer configured with the PDCP duplicationfunction to the DU, respectively.

When the CU and the DU do not activate the PDCP duplication function ofthe radio bearer supporting the PDCP duplication function, the CU isspecifically configured to transmit, via the F1 interface, the datapacket of the radio bearer configured with the PDCP duplication functionto the DU so that the DU transmits, successively via a specified orself-selected RLC entity and a corresponding logic channel thereof, anMAC layer and a cell, the data packet to a user terminal; and the DU isspecifically configured to receive the data packet of the radio bearerconfigured with the PDCP duplication function transmitted via the F1interface by the CU, and transmit, successively via a specified orself-selected RLC entity and a corresponding logic channel thereof, anMAC layer and a cell, the data packet of the radio bearer configuredwith the PDCP duplication function to a user terminal.

When the CU transmits the data packet of the radio bearer configuredwith the PDCP duplication function to the user terminal, thetransmission is realized by a tunnel on the F1 interface or a controlplane message on the F1 interface; and when the CU transmits the datapacket of the radio bearer configured with the PDCP duplication functionto the user terminal, one tunnel on the F1 interface includes aspecified tunnel or a self-selected tunnel.

When the data packet of the radio bearer configured with the PDCPduplication function is uplink data, the DU is configured to transmitthe data packet of the radio bearer configured with the PDCP duplicationfunction to the CU; and the CU is configured to process, by a PDCPlayer, the received data packet of the radio bearer configured with thePDCP duplication function to obtain a PDCP SDU of the radio bearerconfigured with the PDCP duplication function.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the DU isspecifically configured to transmit, by one or two tunnels on the F1interface or a control plane message on the F1 interface and to the CU,two identical data packets of the radio bearer configured with the PDCPduplication function acquired from two different cells, wherein the twoidentical data packets are obtained via physical layers of the cells,MAC layers, two different logic channels and corresponding RLC entitiesthereof.

When the CU and the DU do not activate the PDCP duplication function ofthe radio bearer supporting the PDCP duplication function, the DU isspecifically configured to transmit, via the F1 interface and to the CU,a data packet of the radio bearer configured with the PDCP duplicationfunction acquired from a cell, wherein the data packet is obtained via aphysical layer of the cell, an MAC layer, a logic channel and acorresponding RLC entity thereof, and the CU is specifically configuredto process, by a PDCP layer, the received data packet of the radiobearer configured with the PDCP duplication function to obtain a datapacket of the radio bearer configured with the PDCP duplicationfunction.

The DU transmits, by a tunnel on the F1 interface or a control planemessage on the F1 interface and to the CU, the data packet of the radiobearer configured with the PDCP duplication function acquired from acell, wherein the data packet is obtained via a physical layer of thecell, an MAC layer, a logic channel and a corresponding RLC entitythereof.

One tunnel on the F1 interface includes a specified tunnel or aself-selected tunnel, and the RLC entity includes a specified RLC entityor a self-selected RLC entity.

The data packet of the radio bearer configured with the PDCP duplicationfunction includes: a data packet of a Data Radio Bearer (DRB) configuredwith a PDCP duplication function and/or a data packet of a SignalingRadio Bearer (SRB) configured with a PDCP duplication function.

Based on the base station including a CU and a DU provided by thepresent disclosure, the CU and the DU will be described below bydividing them into functional modules.

A Central Unit (CU) is provided, including:

a transmitting subunit configured to transmit, to a distributed unit(DU), a configuration instruction message of a radio bearer supporting aPDCP duplication function; and

a processing subunit configured to perform, with the DU, transmission ofa data packet of the radio bearer configured with the PDCP duplicationfunction.

When the data packet of the radio bearer configured with the PDCPduplication function is downlink data, the transmitting subunit isconfigured to transmit, by an F1 interface between the CU and the DU,the data packet of the radio bearer configured with the PDCP duplicationfunction.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the transmittingsubunit is specifically configured to transmit, by a tunnel on the F1interface, the data packet of the radio bearer configured with the PDCPduplication function to the DU; or the transmitting subunit isspecifically configured to duplicate the data packet of the radio bearerconfigured with the PDCP duplication function to obtain two identicaldata packets of the radio bearer configured with the PDCP duplicationfunction, and transmit, by a tunnel on the F1 interface, the twoidentical data packets of the radio bearer configured with the PDCPduplication function, respectively; or, specifically configured totransmit, by a tunnel on the F1 interface, the data packet of the radiobearer configured with the PDCP duplication function for two times; orthe transmitting subunit is specifically configured to transmit, by twodifferent tunnels on the F1 interface, the data packet of the radiobearer configured with the PDCP duplication function to the DU for twotimes; or the transmitting subunit is specifically configured totransmit, by a control plane message on the F1 interface, two identicaldata packets of the radio bearer configured with the PDCP duplicationfunction to the DU.

When the CU does not activate the PDCP duplication function of the radiobearer supporting the PDCP duplication function, the transmittingsubunit is specifically configured to transmit, via the F1 interface,the data packet of the radio bearer configured with the PDCP duplicationfunction to the DU so that the DU transmits, successively by a specifiedor self-selected RLC entity and a corresponding logic channel thereof,an MAC layer and a cell, the data packet to a user terminal.

When the transmitting subunit transmits the data packet of the radiobearer configured with the PDCP duplication function to the DU, thetransmission is realized by a tunnel on the F1 interface or a controlplane message on the F1 interface; and when the transmitting subunittransmits the data packet of the radio bearer configured with the PDCPduplication function to the DU, one tunnel on the F1 interface includesa specified tunnel or a self-selected tunnel.

When the data packet of the radio bearer configured with the PDCPduplication function is uplink data, the CU further includes:

a receiving subunit configured to receive the data packet of the radiobearer configured with the PDCP duplication function transmitted by theDU; and

the processing subunit is configured to process, by a PDCP layer, thereceived data packet of the radio bearer configured with the PDCPduplication function to obtain a PDCP SDU of the radio bearer configuredwith the PDCP duplication function.

The configuration instruction message of the radio bearer supporting thePDCP duplication function transmitted to the DU by the transmittingsubunit includes at least one of the following information:

information indicating the support of the PDCP duplication function;part or all of configuration information of at least one RLC entitycorresponding to a data bearer; identifier information and/orconfiguration information of a logic channel corresponding to at leastone RLC entity;

configuration information of at least one tunnel on the F1 interface;

information about a correspondence between at least one tunnel on the F1interface and at least one RLC entity; and

indication information for identifying a duplicated data packet.

The CU further includes:

a receiving subunit configured to receive a configuration responsemessage returned by the DU, wherein the configuration response messageincludes configuration information of at least one tunnel on the F1interface.

The configuration information of at least one tunnel on the F1 interfacecontained in the configuration instruction message is specificallyaddress information for receiving or transmitting, by the CU, the datapacket of the radio bearer supporting the PDCP duplication function;and, the configuration information of at least one tunnel on the F1interface contained in the configuration response message isspecifically address information for receiving or transmitting, on theDU side, the data packet of the radio bearer supporting the PDCPduplication function.

The data packet of the radio bearer configured with the PDCP duplicationfunction includes: a data packet of a data radio bearer configured witha PDCP duplication function and/or a data packet of a signaling radiobearer configured with a PDCP duplication function.

The present disclosure further provides a Distributed Unit (DU),including:

a receiving subunit configured to receive a configuration instructionmessage of a radio bearer supporting a PDCP duplication functiontransmitted by a central unit (CU); and

a processing subunit configured to perform, with the CU, transmission ofa data packet of the radio bearer configured with the PDCP duplicationfunction.

When the data packet of the radio bearer configured with the PDCPduplication function is downlink data, the DU further includes:

the receiving subunit configured to receive, by an F1 interface betweenthe DU and the CU, the data packet of the radio bearer configured withthe PDCP duplication function; and

a transmitting subunit configured to transmit the data packet of theradio bearer configured with the PDCP duplication function to twodifferent cells, respectively.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the receivingsubunit is configured to receive, by a tunnel on the F1 interface, thedata packet of the radio bearer configured with the PDCP duplicationfunction transmitted by the CU; the processing subunit is specificallyconfigured to duplicate the data packet of the radio bearer configuredwith the PDCP duplication function to obtain two identical data packetsof the radio bearer configured with the PDCP duplication function; andthe transmitting subunit is specifically configured to transmit, by twodifferent RLC entities and corresponding logic channels thereof and viaan MAC layer, the two identical data packets of the radio bearerconfigured with the PDCP duplication function to two different cells,respectively.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the receivingsubunit is configured to receive, by a tunnel on the F1 interface, thedata packet of the radio bearer configured with the PDCP duplicationfunction transmitted by the CU; and the transmitting subunit isspecifically configured to transmit, by two different RLC entities andcorresponding logic channels and via an MAC layer, the data packet ofthe radio bearer configured with the PDCP duplication function to twodifferent cells once, respectively.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the receivingsubunit is configured to receive, by one or two tunnels on the F1interface and via the receptions of two times, two identical datapackets of the radio bearer configured with the PDCP duplicationfunction transmitted by the CU; and the transmitting subunit isspecifically configured to transmit, by two different RLC entities andcorresponding logic channels thereof and via an MAC layer, two identicaldata packets of the radio bearer configured with the PDCP duplicationfunction to two different cells, respectively.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the receivingsubunit is configured to receive, by a control plane message on the F1interface and via the receptions of two times, two identical datapackets of the radio bearer configured with the PDCP duplicationfunction transmitted by the CU; and the transmitting subunit isspecifically configured to transmit, by two different RLC entities andcorresponding logic channels thereof and via an MAC layer, two identicaldata packets of the radio bearer configured with the PDCP duplicationfunction to two different cells, respectively.

When the CU and the DU do not activate the PDCP duplication function ofthe radio bearer supporting the PDCP duplication function, the receivingsubunit is specifically configured to receive the data packet of theradio bearer configured with the PDCP duplication function transmittedby the CU via the F1 interface; and the transmitting subunit isspecifically configured to transmit, successively via a specified orself-selected RLC entity and a corresponding logic channel thereof, anMAC layer and a cell, the data packet of the radio bearer configuredwith the PDCP duplication function to a user terminal.

When the data packet of the radio bearer configured with the PDCPduplication function is uplink data, the DU further includes:

a transmitting subunit configured to transmit the data packet of theradio bearer configured with the PDCP duplication function to the CU.

When the CU and the DU activate the PDCP duplication function of theradio bearer supporting the PDCP duplication function, the transmittingsubunit is specifically configured to transmit, by one or two tunnels onthe F1 interface or a control plane message on the F1 interface, twoidentical data packets of the radio bearer configured with the PDCPduplication function acquired from two different cells to the CU,wherein the two identical data packets are obtained by physical layersof the cells, MAC layers, two different logic channels and correspondingRLC entities thereof.

When the CU and the DU do not activate the PDCP duplication function ofthe radio bearer supporting the PDCP duplication function, thetransmitting subunit is specifically configured to transmit, via the F1interface and to the CU, the data packet of the radio bearer configuredwith the PDCP duplication function acquired from a cell, wherein thedata packet is obtained by a physical layer of the cell, an MAC layer, alogic channel and a corresponding RLC entity thereof.

The DU transmits, by a tunnel on the F1 interface or a control planemessage on the F1 interface and to the CU, the data packet of the radiobearer configured with the PDCP duplication function acquired from acell, wherein the data packet is obtained by a physical layer of thecell, an MAC layer, a logic channel and a corresponding RLC entitythereof.

One tunnel on the F1 interface includes a specified tunnel or aself-selected tunnel, and the RLC entity includes a specified RLC entityor a self-selected RLC entity.

The DU further includes:

a transmitting subunit configured to transmit, to the CU, aconfiguration response message carrying configuration information of atleast one tunnel on the F1 interface.

The configuration information of at least one tunnel on the F1 interfacecontained in the configuration response message is specifically addressinformation for receiving by the receiving subunit or transmitting bythe transmitting subunit the data packet of the radio bearer configuredwith the PDCP duplication function.

The data packet of the radio bearer configured with the PDCP duplicationfunction includes: a data packet of a data radio bearer configured witha PDCP duplication function and/or a data packet of a signaling radiobearer configured with a PDCP duplication function.

In the above embodiments, the transmission of a bearer supporting a PDCPduplication function on an F1 interface between a CU and a DU in a basestation is mainly discussed; however, in an actual system, a bearersupporting a PDCP duplication function may also be transmitted on aninterface (e.g., an X2 interface or an Xn interface) between two basestations (e.g., between an eNB and a gNB, between two eNBs, between twogNBs or the like). For the transmission of a bearer supporting a PDCPduplication function on an interface between two base stations, theprocessing procedure thereof is the same as the processing procedure ofthe transmission of a bearer supporting a PDCP duplication function onan F1 interface between a CU and a DU in a base station, and will not bespecifically described here.

Based on this, the present disclosure further provides a datatransmission method supporting a PDCP duplication function, as shown inFIG. 5, including the following steps.

Step 501: A first network equipment transmits, to a second networkequipment, a configuration instruction message of a radio bearersupporting a PDCP duplication function.

Step 502: The first network equipment performs, with the second networkequipment, transmission of a data packet of the radio bearer configuredwith the PDCP duplication function. The first network equipment is afirst base station, and the second network equipment is a second basestation; or, the first network equipment is a CU in a base station, andthe second network equipment is a DU in the base station.

Based on the system and the data transmission method supporting a PDCPduplication function provided by the present disclosure, the followingfive embodiments will be specifically described below. Of course, in thefive embodiments, the description is mainly given for a DU and a CU in abase station.

In the embodiment, the method includes the following steps.

Step A: A gNB-CU transmits, to a gNB-DU, a request message ofconfiguring a data radio bearer supporting a PDCP duplication function,wherein, for each data radio bearer supporting the PDCP duplicationfunction, the message at least contains one or more pieces of thefollowing information:

1) Information indicating the support of the PDCP duplication function,wherein possible implementations are as follows:

way 1: indication information of supporting the PDCP duplicationfunction, wherein the indication information indicates that the dataradio bearer supports the PDCP duplication function;

way 2: type information of the data radio bearer, wherein the typeinformation indicates that the data radio bearer is a data radio bearersupporting the PDCP duplication function; and

way 3: identifier information of the data radio bearer, wherein one ormore identifiers of the data radio bearer supporting the PDCPduplication function are predefined or preconfigured, and the data radiobearer supports the PDCP duplication function if the identifier of thedata radio bearer indicates that the data radio bearer is a data radiobearer supporting the PDCP duplication function.

Further, the information indicating the support of the PDCP duplicationfunction may further include indication information of uplink/downlink.The indication information indicates the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function indownlink, or the support of the PDCP duplication function in both uplinkand the downlink. If the indication information of uplink/downlink isnot included, the information indicating the support of the PDCPduplication function may indicate the support of the PDCP duplicationfunction in both uplink and downlink, the support of the PDCPduplication function in downlink, the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function in adefault direction (in uplink, in downlink or in both uplink anddownlink).

2) Part or all of configuration information of at least one RLC entitycorresponding to the data radio bearer. A data radio bearer supportingthe PDCP duplication function will have two RLC entities. However, theconfiguration information may contain part or all of configurationinformation of one RLC entity, or part or all of configurationinformation of the two RLC entities. For example, in a situation wherethe configuration information contains configuration information of oneRLC entity, it is indicated that the existing configuration informationof the RLC entity of the data radio bearer can be reused and thecontained configuration information of the RLC entity is specific to anewly added RLC entity. In a situation where the configurationinformation contains configuration information of two RLC entities, thenewly received configuration information of the two RLC entities cancover the existing information, if the gNB-DU already has configurationinformation of at least one RLC entity of the data radio bearer; and,the gNB-DU directly uses the newly received configuration information ofthe two RLC entities, if the gNB-DU does not have any information of RLCentities corresponding to the data radio bearer. In addition, theconfiguration information of each RLC entity may contain indicationinformation indicating whether the RLC entity is a main RLC entity (orreferred to as a default RLC entity) (it is possible to not contain theindication information, if an RLC entity is not configured as a main RLCentity; in another way, a main RLC entity does not contain indicationinformation, while a non-main RLC entity will add one piece ofindication information to indicate that this RLC entity is a non-mainRLC entity). The indication information may be optional or mandatory.The indication information has the following functions: for the downlinkdata transmission, the indication information is used for indicating howthe gNB-DU distributes the received PDCP PDUs to two RLC entitiesconfigured for the data radio bearer; while for the uplink datatransmission, the indication information is used for indicating how thegNB-DU distributes, to two RLC entities configured for the data radiobearer, data of the data radio bearer received from different cells. Theindication information can indicate a RLC entity (e.g., a main RLCentity) to be used by the gNB-DU when only one RLC entity needs to beused. For example, when the data radio bearer is configured to support aPDCP duplication function and this function has not been activated, fordownlink data, the PDCP PDU of the data radio bearer received from thegNB-CU is transmitted to only the main RLC entity, if one RLC entity isindicated as a main RLC entity; while for uplink data, the data of thedata radio bearer received by the gNB-DU is transmitted to the main RLCentity via a logic channel corresponding to the main RLC entity. Foranother example, when the data radio bearer is configured to support aPDCP duplication function and this function has been activated, fordownlink data, when a PDCP PDU belonging to the data radio bear isreceived from gNB-CU, the gNB-DU transmits the PDCP PDU to the main RLCentity, if the gNB-DU receives the PDCP PDU of the data radio bearerfrom the gNB-CU for the first time; and the gNB-DU transmits the PDCPPDU to the other RLC entity (the non-main RLC entity), if the gNB-DUreceives the PDCP PDU of the data radio bearer from the gNB-CU for thesecond time.

3) Identifier information and/or configuration information of a logicchannel corresponding to at least one configured RLC entity for the dataradio bearer, wherein the configuration information contains restrictioninformation for mapping the logic channel to indicate that the data ofthis logic channel can be transmitted to only a cell or a carrierindicated by the restriction information.

4) Configuration information of at least one tunnel for the data radiobearer. The information provides information of a tunnel established forthe transmission of data of this data radio bearer on the F1 interface.The data radio bearer supporting the PDCP duplication function will havetwo tunnels. The information contains information of at least one tunnelon the gNB-CU side, and the information of each tunnel containsinformation on the gNB-CU side or address information, for example,gNB-CU GTP tunnel endpoint information (containing the address of atransport layer and a GTP TEID). For example, in a situation whereconfiguration information of one tunnel is contained, it is indicatedthat the existing configuration information of the tunnel of the dataradio bearer can be reused and the contained configuration informationof the tunnel is specific to a newly added tunnel. In a situation whereconfiguration information of two tunnels is contained, the newlyreceived configuration information of two tunnels can cover the existinginformation, if there is already configuration information of at leastone tunnel of the data radio bearer; and, the newly receivedconfiguration information of two tunnels is directly used, if there isno any configuration information of tunnels corresponding to the dataradio bearer. In addition, the information further contains theindication information indicating whether the tunnel is a main tunnel(or a default tunnel) (it is possible to not contain the indicationinformation, if a tunnel is not configured as a main tunnel; in anotherway, the indication information indicating whether the tunnel is a maintunnel (or a default tunnel) is not contained, while one piece ofindication information for indicating that this tunnel is a non-maintunnel will be added in the configuration information of the non-maintunnel, if a tunnel is a main tunnel). The indication information may beoptional or mandatory. The indication information has the followingfunctions: for the downlink data transmission, the indicationinformation is used for indicating how the gNB-CU transmits a PDCP PDUto the gNB-DU; while for the uplink data transmission, the indicationinformation is used for indicating how the gNB-DU transmits a PDCP PDUto the gNB-CU. The indication information may indicate a tunnel (e.g., amain tunnel) to be used between the gNB-CU and the gNB-DU when only onetunnel is required. For example, when the data radio bearer isconfigured to support a PDCP duplication function and this function hasnot been activated, for downlink data, the PDCP PDU of the data radiobearer received from the gNB-CU is transmitted to the gNB-DU through thetunnel, if one tunnel is indicated as a main tunnel; while for uplinkdata, the data of the data radio bearer received by the gNB-DU istransmitted to the gNB-CU only through this tunnel. For another example,when the data radio bearer is configured to support a PDCP duplicationfunction and this function has been activated, for uplink data, the PDCPPDU is transmitted to the gNB-CU through the main tunnel, if an RLCentity obtains a PDCP PDU of the data radio bearer for the first time;and the PDCP PDU is transmitted to the gNB-CU through the other tunnel(the non-main tunnel), if the RLC entity obtains a PDCP PDU of the dataradio bearer for the second time.

5) Information about a correspondence between tunnels and RLC entities.As described above, each data radio bearer has two tunnels, two RLCentities, and identifier and configuration information of a logicchannel corresponding to each RLC entity.

Wherein, the correspondence between RLC entities and tunnels on the F1interface can be expressed in the following two ways:

way 1: each RLC entity corresponds to a tunnel on the F1 interface; forexample, a tunnel 1 corresponds to an RLC entity 1, a tunnel 2corresponds to an RLC entity 2, a main tunnel corresponds to a main RLCentity, a main tunnel corresponds to a non-main RLC entity, or anon-main tunnel corresponds to a main RLC entity; and

way 2: there is no correspondence between RLC entities and tunnels onthe F1 interface.

In accordance with the description of information in the request messagein the step A, the structure of the configuration information of thedata radio bearer can be as follows:

when RLC entities have corresponding tunnels on the F1 interface,

1) information indicating the support of the PDCP duplication function;

2) configuration information of the RLC entity 1;

3) identifier and/or configuration information of a logic channelcorresponding to the RLC entity 1;

4) gNB-CU side information or address information of the tunnel 1corresponding to the RLC entity 1;

5) configuration information of the RLC entity 2;

6) identifier and/or configuration information of a logic channelcorresponding to the RLC entity 2; and

7) gNB-CU side information or address information of the tunnel 2corresponding to the RLC entity 2;

when there is no correspondence between RLC entities and tunnels on theF1 interface,

1) information indicating the support of the PDCP duplication function;

2) configuration information of the RLC entity 1;

3) identifier and/or configuration information of a logic channelcorresponding to the RLC entity 1;

4) configuration information of the RLC entity 2;

5) identifier and/or configuration information of a logic channelcorresponding to the RLC entity 2;

6) gNB-CU side information or address information of the tunnel 1; and

7) gNB-CU side information or address information of the tunnel 2.

Step B: The gNB-DU executes the related configuration, and the gNB-DUfeeds back, to the gNB-CU, a response message of configuring the dataradio bearer supporting the PDCP duplication function, if the gNB-DUaccepts the configuration of the data radio bearer in the step A,wherein the message at least contains the following information:

information about tunnels for the data radio bearer, which providesinformation about a tunnel established for transmitting data of the dataradio bearer on the F1 interface. The information contains gNB-DU sideinformation of at least one established tunnel (e.g., gNB-DU sideinformation of the tunnel 1 and gNB-DU side information of the tunnel2), and the information about each tunnel contains address informationon the gNB-DU side, for example, gNB-DU GTP tunnel endpoint information(containing the address of a transport layer and a GTP TEID). Step C:The PDCP duplication function is activated. This step is optional. Thisstep includes activation of the PDCP duplication function on the gNB-CUside, the gNB-DU side and on the UE side. Possible implementations areas follows.

Way 1: The gNB-CU activates the PDCP duplication function of the dataradio bearer on the gNB-DU side and/or the UE side. The gNB-CU transmitsPDCP duplication function activation information to the gNB-DU and/or aUE. Then, the PDCP duplication function of the data radio bearer isactivated on the gNB-DU side, and data of the data radio bearer will betransmitted according to the configuration information in the steps Aand B; and, the PDCP duplication function of the data radio bearer isalso activated on the UE side, and data of the data radio bearer will betransmitted according to the received RRC configuration message.Further, the activation information may indicate the activation of anuplink PDCP duplication function, the activation of a downlink PDCPduplication function or the activation of uplink and downlink PDCPduplication functions. If there is no indication information in theactivation information, the activation information indicates theactivation of uplink and downlink PDCP duplication functions, theactivation of an uplink PDCP duplication function, the activation of adownlink PDCP duplication function or the activation of PDCP duplicationfunction in a default direction (in uplink, in downlink or in bothuplink and downlink). Here, the activation order is not restricted. Itis possible to activate the PDCP duplication function on the gNB-DUside, followed by the PDCP duplication function on the UE side; or, itis possible to activate the PDCP duplication function on the UE side,followed by the PDCP duplication function on the gNB-DU side; or, it isalso possible to simultaneously activate the PDCP duplication functionon the gNB-DU side and the PDCP duplication function on the UE side. Inaddition, optionally, upon receiving the activation informationtransmitted by the gNB-CU, the gNB-DU may reply whether the activationis successful. If the activation being successful is replied, the PDCPduplication function on the gNB-DU side is activated; or otherwise, thePDCP duplication function on the gNB-DU side is not activated. Further,after the PDCP duplication function is activated, the gNB-CU may alsotransmit deactivation information to the gNB-DU and/or the UE.Optionally, the gNB-DU may reply whether the deactivation is successful.If the deactivation being successful is replied, the PDCP duplicationfunction on the gNB-DU side is stopped; or otherwise, the PDCPduplication function on the gNB-DU side is used continuously.

Way 2: The gNB-DU activates the PDCP duplication function of the dataradio bearer on the gNB-CU side and/or the UE side. The gNB-DU transmitsPDCP duplication function activation information to the gNB-CU and/or aUE. Then, the PDCP duplication function of the data radio bearer isactivated on the gNB-CU side, and data of the data radio bearer will betransmitted according to the configuration information in the steps Aand B (a duplicated PDCP PDU is transmitted to the gNB-DU through the F1interface or a duplicated PDCP PDU transmitted by the gNB-DU isreceived); and, the PDCP duplication function of the data radio beareris also activated on the UE side, and data of the data radio bearer willbe transmitted according to the received RRC configuration message.Further, the activation information may indicate the activation of anuplink PDCP duplication function, the activation of a downlink PDCPduplication function or the activation of uplink and downlink PDCPduplication functions. If there is no indication information in theactivation information, the activation information indicates theactivation of uplink and downlink PDCP duplication functions, theactivation of an uplink PDCP duplication function, the activation of adownlink PDCP duplication function or the activation of PDCP duplicationfunction in a default direction (in uplink or in downlink). Here, theactivation order is not restricted. It is possible to activate the PDCPduplication function on the gNB-DU side, followed by the PDCPduplication function on the UE side; or, it is possible to activate thePDCP duplication function on the UE side, followed by the PDCPduplication function on the gNB-DU side; or, it is possible tosimultaneously activate the PDCP duplication function on the gNB-DU sideand the PDCP duplication function on the UE side. In addition,optionally, upon receiving the activation information transmitted by thegNB-DU, the gNB-CU may reply whether the activation is successful. Ifthe activation being successful is replied, the PDCP duplicationfunction on the gNB-CU side is activated; or otherwise, the PDCPduplication function on the gNB-CU side is not activated. Further, afterthe PDCP duplication function is activated, the gNB-DU may also transmitdeactivation information to the gNB-CU and/or the UE. Optionally, thegNB-CU may reply whether the deactivation is successful. If thedeactivation being successful is replied, the gNB-CU stops the PDCPduplication function; or otherwise, the PDCP duplication function isused continuously.

It is indicated that the PDCP duplication function of the data radiobearer has been activated on the gNB-CU side, the gNB-DU side and the UEside, if the step C has been executed, and a step D will be executed.There are two possibilities, if the step C has not been executed: 1)after the steps A and B have ended, the PDCP duplication function of thedata radio bearer has been activated on the gNB-CU side, the gNB-DU sideand the UE side (the activation on the UE side has been realized by anindividual signaling), and step D will be executed in this case; and, 2)after the steps A and B have ended, the configuration of the PDCPduplication function has been completed on gNB-CU side, the gNB-DU sideand the UE side but this function has not been activated, and step Ewill be executed in this case.

Step D: Data of the data radio bearer having the activated PDCPduplication function is transmitted. This step is performed after thePDCP duplication function of the data radio bearer has been activated(that is, data of the data radio bearer will be transmitted among thegNB-CU, the gNB-DU and the UE according to the configuration of thecorresponding PDCP duplication function). As shown in FIG. 6, this stepincludes the following substeps, if the data radio bearer is downlink.

Substep D-a (downlink): The gNB-CU duplicates a PDCP PDU to obtain twoidentical PDCP PDUs, or transmits a PDCP PDU for two times.

Substep D-b (downlink): The two identical PDCP PDUs obtained in thesubstep D-a (downlink) are transmitted to the gNB-DU by two differenttunnels (e.g., F1-U tunnel 1 and F1-U tunnel 2) on the F1 interface,respectively.

Substep D-c (downlink): The gNB-DU transmits the received two identicalPDCP PDUs to two different RLC entities (e.g., RLC1 and RLC2), the twoidentical PDCP PDUs are then transmitted to an MAC layer by twodifferent logic channels (e.g., a logic channel 1 and a logic channel2), and the MAC layer transmits, by two different cells, data from thetwo different logic channels to two different cells (e.g., a cell 1 anda cell 2, where the two cells may be at different frequencies or atidentical frequencies), respectively. On how the gNB-DU distributes thedata received from two tunnels to two RLC entities, possibleimplementations are as follows.

Way 1: The data on each tunnel is transmitted to the specified RLCentity according to the specified correspondence, if there is aspecified correspondence between each tunnel and each RLC entity. Forexample, data on the tunnel 1 is transmitted to the RLC1, and data onthe tunnel 2 is transmitted to the RLC2.

Way 2: The implementation may be set by the gNB-DU, if there is nospecified correspondence between each tunnel and each RLC entity. As animplementation, the gNB-DU sets that data on the tunnel 1 is transmittedto the RLC1 and data on the tunnel 2 is transmitted to the RLC2. Asanother implementation, for two identical PDCP PDUs received from twotunnels, the first received PDCP PDU is transmitted to the RLC1 and thesecond received PDCP PDU is transmitted to the RLC2. In thisimplementation, the gNB-DU needs to identify whether two PDCP PDUsreceived from two tunnels are identical. As still anotherimplementation, once the gNB-DU receives a data packet (e.g., PDCP PDU1)from one of the two tunnels, the gNB-DU autonomously duplicates the datapacket to obtain two identical data packets and then transmit the twoidentical data packets to two RLC entities (RLC1 and RLC2),respectively, or the gNB-DU autonomously transmits the data packet fortwo times to two RLC entities (RLC 1 and RLC2); hereafter, the gNB-DUcan discard this data packet since this data packet has been transmittedto different RLC entities, if the gNB-DU receives an identical datapacket again (e.g., PDCP PDU1) (here, the gNB-DU also needs to have afunction of identifying whether two PDCP PDUs received from two tunnelsare identical); or, the gNB-DU can duplicate the data packet to obtaintwo identical data packets and then transmit the two identical datapackets to two RLC entities (RLC1 and RLC2), respectively, or the gNB-DUautonomously transmits the data packet for two times to two RLC entities(RLC1 and RLC2). The implementation may also be determined by the gNB-DUaccording to the existing configuration. For example, for two identicalPDCP PDUs, the first received PDU will be transmitted to a specific RLCentity (e.g., RLC1) by the gNB-DU, wherein the specific RLC entity maybe the configured main RLC entity (or the default RLC entity); and, thesecond received PDU will be transmitted to the other RLC entity (thenon-main RLC entity) by the gNB-DU. In this case, the gNB-DU needs toidentify whether two PDCP PDUs received from two tunnels are identical.

This step includes the following substeps, if the data radio bearer isuplink.

Substep D-a (uplink): The gNB-DU receives data from two different cells(e.g., a cell 1 and a cell 2, where the two cells may be at differentfrequencies or at identical frequencies), and the data from the twodifferent cells are processed by a physical layer and an MAC layer andthen transmitted to two different RLC entities (e.g., RLC1 and RLC2) bytwo different logic channels (e.g., a logic channel 1 and a logicchannel 2), respectively.

Substep D-b (uplink): The data processed by the two RLC entities will betransmitted to the gNB-CU by two different tunnels (e.g., a tunnel 1 anda tunnel 2) on the F1 interface. On how the gNB-DU distributes the dataoutput from the two RLC entities to two tunnels, possibleimplementations are as follows.

Way 1: The data output from each RLC entity is transmitted to thespecified tunnel according to the specified correspondence, if there isa specified correspondence between each tunnel and each RLC entity. Forexample, the data output from the RLC1 is transmitted to the gNB-CU viathe tunnel 1, and the data output from the RLC2 is transmitted to thegNB-CU via the tunnel 2.

Way 2: The implementation may be set by the gNB-DU, if there is nospecified correspondence between each tunnel and each RLC entity. As animplementation, the gNB-DU sets that the data output from the RLC1 istransmitted to the gNB-CU via the tunnel 1 and the data output from theRLC2 is transmitted to the gNB-CU via the tunnel 2. As anotherimplementation, for two identical PDCP PDUs output from two RLCentities, the first output PDCP PDU is transmitted to the tunnel 1 andthe second output PDCP PDU is transmitted to the tunnel 2. In thisimplementation, the gNB-DU needs to identify whether two PDCP PDUsoutput from the two RLC entities are identical. As still anotherimplementation, once a data packet (e.g., PDCP PDU1) is output from oneof two RLC entities on the gNB-DU, the gNB-DU autonomously duplicatesthe data packet to obtain two identical data packets and then transmitsthe two identical data packets to two tunnels (a tunnel 1 and a tunnel2), respectively; hereafter, the gNB-DU can discard this data packetsince this data packet has been transmitted to the gNB-CU, or the gNB-DUcan duplicate the data packet to obtain two identical data packets andthen transmit the two identical data packets to two tunnels (a tunnel 1and a tunnel 2), if the gNB-DU receives an identical data packet (e.g.,PDCP PDU1) again (here, the gNB-DU needs to have a function ofidentifying whether two PDCP PDUs output from the two RLC entities areidentical). The implementation may also be determined by the gNB-DUaccording to the existing configuration. For example, for two identicalPDCP PDUs output from two RLC entities, the first output PDU will betransmitted to a specified tunnel (e.g., the tunnel 1) by the gNB-DU,wherein the specified tunnel may be a main tunnel (or referred to as adefault tunnel); while the second output PDU will be transmitted to theother tunnel (e.g., the non-main tunnel) by the gNB-DU. In thisimplementation, the gNB-DU needs to identify whether two PDCP PDUsoutput from the two RLC entities are identical.

Substep D-c (uplink): The gNB-CU processes the received PDCP PDUs (e.g.,discards a duplicated PDCP PDU) by a PDCP layer to obtain a PDCP SDU.

Step E: Data of the data radio bearer configured with the PDCPduplication function which has not been activated is transmitted. Forthe downlink data transmission, implementations may be as follows.

Way 1: The gNB-CU transmits, by the specified tunnel (e.g., the maintunnel or default tunnel) on the F1 interface, a PDCP PDU of the dataradio bearer to the specified RLC entity (e.g., the main RLC entity ordefault RLC entity), and the PDCP PDU is transmitted to an MAC layer viaa logic channel corresponding to the specified RLC entity and thentransmitted to a user via a cell, if a tunnel (e.g., the main tunnel ordefault tunnel) and an RLC entity (e.g., the main RLC entity or defaultRLC entity) to be used when the PDCP duplication function is configuredbut not activated have been specified in the step A and/or B.

Way 2: the gNB-CU transmits, by the specified tunnel (e.g., the maintunnel or default tunnel) on the F1 interface, a PDCP PDU of the dataradio bearer to gNB-DU, the gNB-DU autonomously selects a configured RLCentity, and the PDCP PDU is transmitted to an MAC layer via a logicchannel corresponding to this RLC entity and then transmitted to a uservia a cell, if a tunnel (e.g., the main tunnel or default tunnel) to beused when the PDCP duplication function is configured but not activatedhas been specified in the step A and/or B but an RLC entity to be usedis not specified.

Way 3: the gNB-CU autonomously determines a configured tunnel andtransmits a PDCP PDU of the data radio bearer to the gNB-DU through thistunnel, the gNB-DU transmits the received PDCP PDU to the specified RLCentity (e.g., the main RLC entity or default RLC entity), and the PDCPPDU is transmitted to an MAC layer via a logic channel corresponding tothe specified RLC entity and then transmitted to a user via a cell, ifan RLC entity (e.g., the main RLC entity or default RLC entity) to beused when the PDCP duplication function is configured but not activatedhas been specified in the step A and/or B but a tunnel is not specified.

Way 4: the CU autonomously determines a configured tunnel and transmitsa PDCP PDU of the data radio bearer to the gNB-DU through this tunnel,the gNB-DU autonomously selects a configured RLC entity, and the PDCPPDU is transmitted to an MAC layer via a logic channel corresponding tothis RLC entity and then transmitted to a user via a cell, if a tunneland an RLC entity to be used when the PDCP duplication function isconfigured but not activated have not been specified in the step Aand/or B.

For the uplink data transmission, implementations may be as follows.

Way 1: The gNB-DU transmits, via a specified logic channel (thespecified logic channel corresponds to the specified RLC entity) and tothe specified RLC entity for processing (e.g., the main RLC entity ordefault RLC entity), the data of the data radio bearer which is receivedfrom a cell and processed by a physical layer and an MAC layer, and theprocessed PDCP PDU is transmitted to the gNB-CU by the specified tunnel(e.g., the main tunnel or default tunnel) on the F1 interface and thenprocessed by a PDCP layer to obtain a PDCP SDU, if a tunnel (e.g., themain tunnel or default tunnel) and an RLC entity (e.g., the main RLCentity or default RLC entity) to be used when the PDCP duplicationfunction is configured but not activated have been specified in the stepA and/or B.

Way 2: The gNB-DU transmits, via a logic channel and to a correspondingRLC entity for processing, the data of the data radio bearer which isreceived from a cell and processed by a physical layer and an MAC layer,and the processed PDCP PDU is transmitted to the gNB-CU by the specifiedtunnel (e.g., the main tunnel or default tunnel) on the F1 interface andthen processed by a PDCP layer to obtain a PDCP SDU, if a tunnel (e.g.,the main tunnel or default tunnel) to be used when the PDCP duplicationfunction is configured but not activated has been specified in the stepA and/or B but an RLC entity is not specified.

Way 3: the gNB-DU transmits, via a specified logic channel (thespecified logic channel corresponds to the specified RLC entity) and tothe specified RLC entity for processing (e.g., the main RLC entity ordefault RLC entity), the data which is received from a cell andprocessed by a physical layer and an MAC layer, and the processed PDCPPDU is transmitted to the gNB-CU by a tunnel (which is autonomouslyselected by the gNB-DU) on the F1 interface and then processed by a PDCPlayer to obtain a PDCP SDU, if an RLC entity (e.g., the main RLC entityor default RLC entity) to be used when the PDCP duplication function isconfigured but not activated has been specified in the step A and/or Bbut a tunnel is not specified.

Way 4: the gNB-DU transmits, via a logic channel and to a correspondingRLC entity for processing, the data of the data radio bearer which isreceived from a cell and processed by a physical layer and an MAC layer,and the processed PDCP PDU is transmitted to the gNB-CU by a tunnel(which is autonomously selected by the gNB-DU) on the F1 interface andthen processed by a PDCP layer to obtain a PDCP SDU, if a tunnel and anRLC entity to be used when the PDCP duplication function is configuredbut not activated have not been specified in the step A and/or B.

The message names in the steps A and B are merely exemplary, and theinvolved configuration information can be carried in other messages fortransmission, for example, a UE context setup request and a UE contextsetup response, a bearer setup request and a bearer setup response, a DLRRC message transfer and a UL RRC message transfer, or the like.

In addition, the existing configuration of the data radio bearer can bemodified by the steps A and B. In order to improve the reliability ofdata transmission of this data radio bearer, it is required to configurethe data radio bearer as a data radio bearer supporting the PDCPduplication function, if the data radio bearer has been configured as anordinary bearer which does not support the PDCP duplication function. Inthis case, the configuration of this data radio bearer can be modifiedby the steps A and B, that is, the configuration messages in the steps Aand B are transmitted through messages, such as a bearer modificationrequest and a bearer modification response. In another way, in the stepsA and B, only the newly added information or the configurationinformation to be modified is contained. For example, when this dataradio bearer does not support the PDCP duplication function, thefollowing information has been configured: configuration information ofthe RLC entity 1;

identifier information of a logic channel corresponding to the RLCentity 1;

configuration information of a logic channel corresponding to the RLCentity 1; andgNB-CU side and gNB-DU side tunnel information of a tunnel 1 on the F1interface established for the data radio bearer.

When the data radio bearer will be configured as a data radio bearersupporting the PDCP duplication function, based on the existingconfiguration information, the modified existing configurationinformation and the newly added information will be transmitted to thegNB-DU in the step A. For example, the modified existing configurationinformation includes:

updated part of the configuration information of the RLC entity 1, forexample, added indication information for indicating whether the entityis a main RLC entity;

updated part of the configuration information of the logic channelcorresponding to the RLC entity 1, for example, added restrictioninformation for mapping the logic channel; and updated part of theinformation of the tunnel 1 on the F1 interface established for the dataradio bearer, for example, added indication information for indicatingwhether the tunnel is a main tunnel.

The newly added information includes:

configuration information of the RLC entity 2;

identifier information of a logic channel corresponding to the RLCentity 2;

configuration information of a logic channel corresponding to the RLCentity 2; and

CU side tunnel information of a tunnel 2 on the F1 interface establishedfor the data radio bearer.

The information transmitted by the gNB-DU in the step B includes:

gNB-DU side tunnel information of the tunnel 2 on the F1 interfaceestablished for the data radio bearer.

In the last embodiment, two tunnels are established for each data radiobearer, and two identical PDCP PDUs obtained by duplication (or two PDCPPDUs obtained by transmitting a PDCP PDU for two times) will betransmitted by two different tunnels; however, in this embodiment, twoidentical PDCP PDUs obtained by duplication (or two PDCP PDUs obtainedby transmitting a PDCP PDU for two times) will be transmitted by a sametunnel, and in a gNB-DU, two RLC entities and an identifier and/orconfiguration of a logic channel corresponding to each RLC entity areconfigured for the data radio bearer. The method includes the followingsteps.

Step A: A gNB-CU transmits, to a gNB-DU, a request message ofconfiguring of a data radio bearer supporting a PDCP duplicationfunction, wherein, for each data radio bearer supporting the PDCPduplication function, the message at least contains one or more piecesof the following information.

1) Information indicating the support of the PDCP duplication function,wherein possible implementations are as follows:

way 1: indication information of supporting the PDCP duplicationfunction, wherein the indication information indicates that the dataradio bearer supports the PDCP duplication function;

way 2: type information of the data radio bearer, wherein the typeinformation indicates that the data radio bearer is a data radio bearersupporting the PDCP duplication function; and

way 3: identifier information of the data radio bearer, wherein one ormore identifiers of the data radio bearer supporting the PDCPduplication function are predefined or preconfigured, and the data radiobearer supports the PDCP duplication function if the identifier of thedata radio bearer indicates that the data radio bearer is a data radiobearer supporting the PDCP duplication function.

Further, the information indicating the support of the PDCP duplicationfunction may further include indication information of uplink/downlink.The indication information indicates the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function indownlink, or the support of the PDCP duplication function in both uplinkand the downlink. If the indication information of uplink/downlink isnot included, the information indicating the support of the PDCPduplication function may indicate the support of the PDCP duplicationfunction in both uplink and downlink, the support of the PDCPduplication function in downlink, the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function in adefault direction (in uplink, in downlink or in both uplink anddownlink).

2) Part or all of configuration information of at least one RLC entitycorresponding to the data radio bearer. The data radio bearer supportingthe PDCP duplication function will have two RLC entities, but theconfiguration information can contain part or all of configurationinformation of one RLC entity or contain part or all of configurationinformation of two RLC entities (it is indicated that the configurationinformation not contained in the configuration information can reuse theexisting configuration, if only part of configuration information iscontained in the configuration information). For example, in a situationwhere the configuration information of one RLC entity is contained, itis indicated that the existing configuration information of the RLCentity of the data radio bearer can be reused and the containedconfiguration information of the RLC entity is specific to a newly addedRLC entity. In a situation where the configuration information of twoRLC entities is contained, the newly received configuration informationof the two RLC entities can cover the existing information, if thegNB-DU already has configuration information of at least one RLC entityof the data radio bearer; and, the gNB-DU directly uses the newlyreceived configuration information of the two RLC entities, if thegNB-DU does not have any information of RLC entities corresponding tothe data radio bearer. In addition, the configuration information ofeach RLC entity may contain indication information for indicatingwhether the RLC entity is a main RLC entity (or referred to as a defaultRLC entity) (it is possible to not contain the indication information,if an RLC entity is not configured as a main RLC entity; in another way,a main RLC entity does not contain indication information, while anon-main RLC entity will contain one piece of indication information toindicate that this RLC entity is a non-main RLC entity). The indicationinformation may be optional or mandatory. The indication information hasthe following functions: for the downlink data transmission, theindication information is used for indicating how the gNB-DU distributesthe received PDCP PDU to two RLC entities configured for the data radiobearer; while for the uplink data transmission, the indication messageis used for indicating how the gNB-DU distributes, to two RLC entitiesconfigured for the data radio bearer, data of the data radio bearerreceived from different cells. The indication information can indicate aRLC entity (e.g., a main RLC entity) to be used by the gNB-DU when onlyone RLC entity needs to be used. For example, for downlink data, thePDCP PDU of the data radio bearer received from the gNB-CU istransmitted to only the main RLC entity, if an RLC entity is indicatedas a main RLC entity, and when the data radio bearer is configured tosupport a PDCP duplication function and this function has not beenactivated; while for uplink data, all data of the data radio bearerreceived by the gNB-DU is transmitted to the main RLC entity. Foranother example, when the data radio bearer is configured to support aPDCP duplication function and this function has been activated, fordownlink data, the gNB-DU transmits the PDCP PDU to the main RLC entity,if the gNB-DU receives a PDCP PDU of the data radio bearer from thegNB-CU for the first time; and the gNB-DU transmits the PDCP PDU to theother RLC entity (the non-main RLC entity), if the gNB-DU receives aPDCP PDU of the data radio bearer from the gNB-CU for the second time.

3) Identifier information and/or configuration information of a logicchannel corresponding to at least one configured RLC entity for the dataradio bearer, wherein the configuration information contains restrictioninformation for mapping the logic channel to indicate that the data ofthis logic channel can be transmitted to only a cell or a carrierindicated by the restriction information.

4) Configuration information of a tunnel for the data radio bearer. Theinformation provides information about a tunnel established for thetransmission of data of this data radio bearer on the F1 interface. Theinformation contains information of one tunnel on the gNB-CU side, forexample, gNB-CU GTP tunnel endpoint information (including the addressof a transport layer and a GTP TEID).

5) Indication information for identifying a duplicated PDCP PDU. Theindication information indicates the kind of information according towhich the gNB-DU identifies whether the received PDCP PDUs areidentical. For example, the indication information indicates that thegNB-DU identifies, according to a sequence number of G-PDU, a sequencenumber of the user plane of the F1 interface or a PDCP SN in an extendedheader contained in the GTP-PDU, whether the received two PDCP PDUs aretwo identical PDUs. The information is optional. The gNB-DU can beidentified by a default setup, if the information is not contained. Thedefault setup can be default identification according to the sequencenumber of the G-PDU, default identification according to the sequencenumber of the user plane of the F1 interface, or default identificationaccording to the PDCP SN in the extended header contained in theGTP-PDU, or default identification by comparing the received PDCP PDUs.

Step B: The gNB-DU executes the related configuration, and the gNB-DUfeeds back, to the gNB-CU, a response message of configuring the dataradio bearer supporting the PDCP duplication function in order toindicate whether the gNB-DU accepts the configuration of the data radiobearer in the step A, if the gNB-DU accepts the configuration of thedata radio bearer in the step A. This response message is optional. Theresponse message contains gNB-DU side information of a tunnel, forexample, gNB-DU GTP tunnel endpoint information (including the addressof a transport layer and a GTP TEID).

Step C: The PDCP duplication function is activated. This step isoptional. This step includes activation of the PDCP duplication functionon the gNB-CU side, the gNB-DU side and the UE side. Possibleimplementations are as follows.

Way 1: The gNB-CU activates the PDCP duplication function of the dataradio bearer on the gNB-DU side and/or the UE side. The gNB-CU transmitsPDCP duplication function activation information to the gNB-DU and/or aUE. Then, the PDCP duplication function of the data radio bearer isactivated on the gNB-DU side, and data of the data radio bearer will betransmitted according to the configuration information in the steps Aand B; and, the PDCP duplication function of the data radio bearer isalso activated on the UE side, and data of the data radio bearer will betransmitted according to the received RRC configuration message.Further, the activation information may indicate the activation of anuplink PDCP duplication function, the activation of a downlink PDCPduplication function or the activation of uplink and downlink PDCPduplication functions. If there is no indication information in theactivation information, the activation information indicates theactivation of uplink and downlink PDCP duplication functions, theactivation of an uplink PDCP duplication function, the activation of adownlink PDCP duplication function or the activation of PDCP duplicationfunction in a default direction (in uplink, in downlink or in bothuplink and downlink). Here, the activation order is not restricted. Itis possible to activate the PDCP duplication function on the gNB-DUside, followed by the PDCP duplication function on the UE side; or, itis possible to activate the PDCP duplication function on the UE side,followed by the PDCP duplication function on the gNB-DU side; or, it isalso possible to simultaneously activate the PDCP duplication functionon the gNB-DU side and the PDCP duplication function on the UE side. Inaddition, optionally, upon receiving the activation informationtransmitted by the gNB-CU, the gNB-DU may reply whether the activationis successful. If the activation being successful is replied, the PDCPduplication function on the gNB-DU side is activated; or otherwise, thePDCP duplication function on the gNB-DU side is not activated. Further,after the PDCP duplication function is activated, the gNB-CU may alsotransmit deactivation information to the gNB-DU and/or the UE.Optionally, the gNB-DU may reply whether the deactivation is successful.If the deactivation being successful is replied, the PDCP duplicationfunction on the gNB-DU side is stopped; or otherwise, the PDCPduplication function is used continuously.

Way 2: The gNB-DU activates the PDCP duplication function of the dataradio bearer on the gNB-CU side and/or the UE side. The gNB-DU transmitsPDCP duplication function activation information to the gNB-CU and/or aUE. Then, the PDCP duplication function of the data radio bearer isactivated on the gNB-CU side, and data of the data radio bearer will betransmitted according to the configuration information in the steps Aand B (a duplicated PDCP PDU is transmitted to the gNB-DU through the F1interface or a duplicated PDCP PDU transmitted by the gNB-DU isreceived); and, the PDCP duplication function of the data radio beareris also activated on the UE side, and data of the data radio bearer willbe transmitted according to the received RRC configuration message.Further, the activation information may indicate the activation of anuplink PDCP duplication function, the activation of a downlink PDCPduplication function or the activation of uplink and downlink PDCPduplication functions. If there is no indication information in theactivation information, the activation information indicates theactivation of uplink and downlink PDCP duplication functions, theactivation of an uplink PDCP duplication function, the activation of adownlink PDCP duplication function or the activation of PDCP duplicationfunction in a default direction (in uplink, in downlink or in bothuplink and downlink). Here, the activation order is not restricted. Itis possible to activate the PDCP duplication function on the gNB-DUside, followed by the PDCP duplication function on the UE side; or, itis possible to activate the PDCP duplication function on the UE side,followed by the PDCP duplication function on the gNB-DU side; or, it isalso possible to simultaneously activate the PDCP duplication functionon the gNB-DU side and the PDCP duplication function on the UE side. Inaddition, optionally, upon receiving the activation informationtransmitted by the gNB-DU, the gNB-CU may reply whether the activationis successful. If the activation is successful, the PDCP duplicationfunction on the gNB-CU side is activated; or otherwise, the PDCPduplication function on the gNB-CU side is not activated. Further, afterthe PDCP duplication function is activated, the gNB-DU may also transmitdeactivation information to the gNB-CU and/or the UE. Optionally, thegNB-CU may reply whether the deactivation is successful. If thedeactivation is successful, the PDCP duplication function on the gNB-CUside is stopped; or otherwise, the PDCP duplication function is usedcontinuously.

It is indicated that the PDCP duplication function of the data radiobearer has been activated on the gNB-CU side, the gNB-DU side and the UEside, if the step C has been executed, and step D will be executed.There are two possibilities, if the step C has not been executed: 1)after the steps A and B have ended, the PDCP duplication function of thedata radio bearer has been activated on the gNB-CU side, the gNB-DU sideand the UE side (the activation on the UE side has been realized by anindividual signaling), and step D will be executed in this case; and, 2)after the steps A and B have ended, the configuration of the PDCPduplication function has been completed on the gNB-CU side, the gNB-DUside and the UE side but this function has not been activated, and stepE will be executed in this case.

Step D: Data of the data radio bearer having the activated PDCPduplication function is transmitted. This step is performed after thePDCP duplication function of the data radio bearer has been activated(that is, data of the data radio bearer will be transmitted among thegNB-CU, the gNB-DU and the UE according to the configuration of thecorresponding PDCP duplication function). This step includes thefollowing substeps, if the data radio bearer is downlink.

Substep D-a (downlink): The gNB-CU duplicates a PDCP PDU to obtain twoidentical PDCP PDUs, or transmits a PDCP PDU for two times to obtain twoidentical PDCP PDUs.

Substep D-b (downlink): The two identical PDCP PDUs obtained in thesubstep D-a (downlink) are transmitted to the gNB-DU through a tunnel onthe F1 interface, and an identical identifier is added to the twoidentical PDCP PDUs to assist the gNB-DU in identifying the twoidentical PDCP PDUs. For example, the two identical PDCP PDUs can beidentified by a G-PDU sequence number, and in this case, a same G-PDUsequence number is assigned to the two identical PDCP PDUs during thegeneration of a G-PDU; the two identical PDCP PDUs can also beidentified by a sequence number of the user plane of the F1 interface,and in this case, a same sequence number of the user plane of the F1interface is assigned to the two identical PDCP PDUs during thegeneration of a data packet of the user plane of the F1 interface; or,the two identical PDCP PDUs can also be identified by a PDCP SN in anextended header contained in the GTP-PDU, and in this case, an extendedheader having a PDCP SN identifier is contained in the GTP-PDU. Inaddition, the gNB-CU can also add no identifier to the two identicalPDCP PDUs, and identical PDCP PDUs can be judged by the gNB-DU itself.

Substep D-c (downlink): The gNB-DU identifies two identical PDCP PDUs.The two identical PDCP PDUs can be identified according to theindication information for identifying a duplicated PDCP PDU containedin the configuration information in the step A; or, identical PDCP PDUscan be identified according to a default setup (the default setup can bedefault identification according to the sequence number of the G-PDU, ordefault identification according to the sequence number of the userplane of the F1 interface, or default identification according to thePDCP SN in the extended header contained in the GTP-PDU); or, tworeceived PDCP PDUs are compared to judge whether the two PDCP PDUs areidentical. The gNB-DU transmits the received two identical PDCP PDUs totwo different RLC entities (e.g., RLC1 and RLC2), the two identical PDCPPDUs are then transmitted to an MAC layer by two different logicchannels (e.g., a logic channel 1 and a logic channel 2), and the MAClayer transmits, by physical layers of two different cells, data fromthe two different logic channels to two different cells (e.g., a cell 1and a cell 2, where the two cells may be at different frequencies or atidentical frequencies), respectively. On how the gNB-DU distributes thereceived data to two RLC entities, possible implementations are asfollows.

Way 1: The gNB-DU makes a decision according to the existingconfiguration. For example, for two identical PDCP PDUs, the firstreceived PDU will be transmitted to a specific RLC entity (e.g., RLC1)by the gNB-DU, wherein the specific RLC entity may be the configuredmain RLC entity (or the default RLC entity); while the second receivedPDU will be transmitted to the other RLC entity (the non-main RLCentity) by the gNB-DU.

Way 2: The implementation is set by the gNB-DU. As an implementation,for two identical PDCP PDUs, the first received PDCP PDU is transmittedto the RLC1 and the second received PDCP PDU is transmitted to the RLC2.As another implementation, once the gNB-DU receives a data packet (e.g.,PDCP PDU1) from a tunnel, the gNB-DU autonomously duplicates the datapacket to obtain two identical data packets and then transmits the twoidentical data packets to two RLC entities (RLC1 and RLC2),respectively; or, the gNB-DU autonomously transmits the data packet fortwo times to two RLC entities (RLC1 and RLC2), respectively. Hereafter,the gNB-DU may discard this data packet since this data packet has beentransmitted to different RLC entities, if the gNB-DU receives anidentical data packet (e.g., PDCP PDU1) again;

or, the gNB-DU duplicates this data packet to obtain two identical datapackets and then transmits the two identical data packets to two RLCentities (RLC1 and RLC2), or the gNB-DU autonomously transmits this datapacket for two times to two RLC entities (RLC1 and RLC2), respectively.

This step includes the following substeps, if the data radio bearer isuplink.

Substep D-a (uplink): The gNB-DU receives data from two different cells(e.g., a cell 1 and a cell 2, where the two cells may be at differentfrequencies or at identical frequencies), and the data from the twodifferent cells are processed by a physical layer and an MAC layer andthen transmitted to two different RLC entities (e.g., RLC1 and RLC2) bytwo different logic channels (e.g., a logic channel 1 and a logicchannel 2), respectively.

Substep D-b (uplink): The data processed by the two RLC entities will betransmitted to the gNB-CU through a tunnel on the F1 interface.

Substep D-c (uplink): The gNB-CU processes the received PDCP PDUs (e.g.,discarding the duplicated PDCP PDU) by a PDCP layer to obtain a PDCPSDU.

Step E: Data of the data radio bearer configured with the PDCPduplication function which has not been activated is transmitted. Forthe downlink data transmission, implementations may be as follows.

Way 1: The gNB-CU transmits, by a tunnel on the F1 interface, a PDCP PDUof the data radio bearer to the specified RLC entity (e.g., the main RLCentity or default RLC entity), and the PDCP PDU is transmitted to an MAClayer via a logic channel corresponding to the specified RLC entity andthen transmitted to a user via a cell, if an RLC entity (e.g., the mainRLC entity or default RLC entity) to be used when the PDCP duplicationfunction is configured but not activated has been specified in the stepA and/or B.

Way 2: The gNB-CU transmits a PDCP PDU of the data radio bearer to thegNB-DU through a tunnel, the gNB-DU autonomously selects a configuredRLC entity, and the PDCP PDU is transmitted to an MAC layer via a logicchannel corresponding to this RLC entity and then transmitted to a uservia a cell, if an RLC entity to be used when the PDCP duplicationfunction is configured but not activated has not been specified in thestep A and/or B.

For the uplink data transmission, implementations may be as follows.

Way 1: The gNB-DU transmits, via a specified logic channel (thespecified logic channel corresponds to the specified RLC entity) and tothe specified RLC entity (e.g., the main RLC entity or default RLCentity), the data of the data radio bearer which is received from a celland processed by a physical layer and an MAC layer, and the processedPDCP PDU is transmitted to the gNB-CU by a tunnel on the F1 interfaceand then processed by a PDCP layer to obtain a PDCP SDU, if an RLCentity (e.g., the main RLC entity or default RLC entity) to be used whenthe PDCP duplication function is configured but not activated has beenspecified in the step A and/or B.

Way 2: The gNB-DU transmits, via a logic channel and to a correspondingRLC entity (the logic channel and the RLC entity are autonomouslydetermined by the gNB-DU), the data of the data radio bearer which isreceived from a cell and processed by a physical layer and an MAC layer,and the processed PDCP PDU is transmitted to the gNB-CU through a tunnelon the F1 interface by the gNB-DU and then processed by a PDCP layer toobtain a PDCP SDU, if an RLC entity to be used when the PDCP duplicationfunction is configured but not activated has not been specified in thestep A and/or B.

The message names in the steps A and B are merely exemplary, and theinvolved configuration information may be carried in other messages fortransmission, for example, a UE context setup request and a UE contextsetup response, a bearer setup request and a bearer setup response, a DLRRC message transfer and a UL RRC message transfer, or the like.

In addition, the existing configuration of the data radio bearer can bemodified by the steps A and B. In order to improve the reliability ofdata transmission of this data radio bearer, it is required to configurethe data radio bearer as a data radio bearer supporting the PDCPduplication function, if the data radio bearer has been configured as anordinary bearer which does not support the PDCP duplication function. Inthis case, the configuration of this data radio bearer can be modifiedby the steps A and B, that is, the configuration messages in the steps Aand B are transmitted by a bearer modification request and a bearermodification response. In another way, in the steps A and B, only thenewly added information or the configuration information to be modifiedis contained. For example, when this data radio bearer does not supportthe PDCP duplication function, the following information has beenconfigured:

configuration information of the RLC entity 1;

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 1; and

gNB-CU side and gNB-DU side tunnel information of a tunnel 1 on the F1interface established for the data radio bearer.

When the data radio bearer will be configured as a data radio bearersupporting the PDCP duplication function, based on the existingconfiguration information, the modified existing configurationinformation and the newly added information will be transmitted to thegNB-DU in the step A. For example, the modified existing configurationinformation includes:

updated part of the configuration information of the RLC entity 1, forexample, added indication information for indicating whether the entityis a main RLC entity; and updated part of the configuration informationof the logic channel corresponding to the RLC entity 1, for example,added restriction information for mapping the logic channel.

The newly added information includes:

configuration information of the RLC entity 2; and

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 2.

In this embodiment, a data radio bearer is configured with a PDCPduplication function, and on an F1 interface, a tunnel is establishedfor the data radio bearer to transmit data of this data radio bearer. Ina DU, two RLC entities and an identifier and/or configuration of a logicchannel corresponding to each RLC entity are configured for this dataradio bearer. For downlink transmission, a DU will duplicate eachreceived PDCP PDU to obtain two identical PDCP PDUs, or the DU willtransmit each PDCP PDU for two times (in this method, the CU does notduplicate the PDCP PDU). The method includes the following steps.

Step A: A gNB-CU transmits, to a gNB-DU, a request message ofconfiguring a data radio bearer supporting a PDCP duplication function,wherein, for each data radio bearer supporting the PDCP duplicationfunction, the message at least contains one or more pieces of thefollowing information.

1) Information indicating the support of the PDCP duplication function,wherein possible implementations are as follows:

way 1: indication information of supporting the PDCP duplicationfunction, wherein the indication information indicates that the dataradio bearer supports the PDCP duplication function;

way 2: type information of the data radio bearer, wherein the typeinformation indicates that the data radio bearer is a data radio bearersupporting the PDCP duplication function; and

way 3: identifier information of the data radio bearer, wherein one ormore identifiers of the data radio bearer supporting the PDCPduplication function are predefined or preconfigured, and the data radiobearer supports the PDCP duplication function if the identifier of thedata radio bearer indicates that the data radio bearer is a data radiobearer supporting the PDCP duplication function.

Further, the information indicating the support of the PDCP duplicationfunction may further include indication information of uplink/downlink.The indication information indicates the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function indownlink, or the support of the PDCP duplication function in both uplinkand the downlink. If the indication information of uplink/downlink isnot included, the information indicating the support of the PDCPduplication function may indicate the support of the PDCP duplicationfunction in uplink and downlink, the support of the PDCP duplicationfunction in downlink, the support of the PDCP duplication function inuplink, or the support of the PDCP duplication function in a defaultdirection (in uplink, in downlink or in both uplink and downlink).

2) Part or all of configuration information of at least one RLC entitycorresponding to the data radio bearer. The data radio bearer supportingthe PDCP duplication function will have two RLC entities, but theconfiguration message can contain part or all of configurationinformation of one RLC entity or contain part or all of configurationinformation of two RLC entities (it is indicated that the configurationinformation not contained in the configuration message can reuse theexisting configuration, if only part of configuration information iscontained in the configuration information). For example, in a situationwhere the configuration information of one RLC entity is contained, itis indicated that the existing configuration information of the RLCentity of the data radio bearer can be reused and the containedconfiguration information of the RLC entity is specific to a newly addedRLC entity. In a situation where the configuration information of twoRLC entities is contained, the newly received configuration informationof the two RLC entities can cover the existing information, if thegNB-DU already has configuration information of at least one RLC entityof the data radio bearer; and, the gNB-DU directly uses the newlyreceived configuration information of the two RLC entities, if thegNB-DU does not have any information of RLC entities corresponding tothe data radio bearer. In addition, the configuration information ofeach RLC entity may contain indication information for indicatingwhether the RLC entity is a main RLC entity (or referred to as a defaultRLC entity) (it is possible to not contain the indication information,if an RLC entity is not configured as a main RLC entity; in another way,a main RLC entity does not contain indication information, while anon-main RLC entity will contain one piece of indication information toindicate that this RLC entity is a non-main RLC entity). The indicationinformation may be optional or mandatory. The indication information hasthe following functions: for the downlink data transmission, theindication information is used for indicating how the gNB-DU distributesthe received PDCP PDU to two RLC entities configured for the data radiobearer; while for the uplink data transmission, the indicationinformation is used for indicating how the gNB-DU distributes, to twoRLC entities configured for the data radio bearer, data of the dataradio bearer received from different cells. The indication informationcan indicate a RLC entity (e.g., a main RLC entity) to be used by thegNB-DU when only one RLC entity needs to be used. For example, fordownlink data, the PDCP PDU of the data radio bearer received from thegNB-CU is transmitted to only the main RLC entity, if an RLC entity isindicated as a main RLC entity, and when the data radio bearer isconfigured to support a PDCP duplication function and this function hasnot been activated; while for uplink data, all data of the data radiobearer received by the gNB-DU is transmitted to the main RLC entity. Foranother example, when the data radio bearer is configured to support aPDCP duplication function and this function has been activated, fordownlink data, the gNB-DU transmits the PDCP PDU to the main RLC entity,if the gNB-DU receives a PDCP PDU of the data radio bearer from thegNB-CU for the first time; and the gNB-DU transmits the PDCP PDU to theother RLC entity (the non-main RLC entity), if the gNB-DU receives aPDCP PDU of the data radio bearer from the gNB-CU for the second time.

3) Identifier information and/or configuration information of a logicchannel corresponding to at least one configured RLC entity for the dataradio bearer, wherein the configuration information contains restrictioninformation for mapping the logic channel, for indicating that the dataof this logic channel only can be transmitted to a cell or a carrierindicated by the restriction information.

4) Configuration information of a tunnel for the data radio bearer. Theinformation provides information about a tunnel established for thetransmission of data of this data radio bearer on the F1 interface. Theinformation contains information of a tunnel on gNB-CU side, forexample, gNB-CU GTP tunnel endpoint information (including the addressof a transport layer and a GTP TEID).

Step B: The gNB-DU executes the related configuration, and the gNB-DUfeeds back, to the gNB-CU, a response message of configuring the dataradio bearer supporting the PDCP duplication function in order toindicate whether the gNB-DU accepts the configuration of the data radiobearer in the step A, if the gNB-DU accepts the configuration of thedata radio bearer in the step A. This response message is optional. Theresponse message may contain gNB-DU side information of a tunnel, forexample, gNB-DU GTP tunnel endpoint information (including the addressof a transport layer and a GTP TEID).

Step C: The PDCP duplication function is activated. This step isoptional. This step includes activation of the PDCP duplication functionon the gNB-DU side and the UE side. Possible implementations are asfollows.

Way 1: The gNB-CU activates the PDCP duplication function of the dataradio bearer on the gNB-DU side and/or the UE side. The gNB-CU transmitsPDCP duplication function activation information to the gNB-DU and/or aUE. Then, the PDCP duplication function of the data radio bearer isactivated on the gNB-DU side, and data of the data radio bearer will betransmitted according to the configuration information in the steps Aand B; and, the PDCP duplication function of the data radio bearer isalso activated on the UE side, and data of the data radio bearer will betransmitted according to the received RRC configuration information.Further, the activation information may indicate the activation of anuplink PDCP duplication function, the activation of a downlink PDCPduplication function or the activation of uplink and downlink PDCPduplication functions. If there is no indication information in theactivation information, the activation information indicates theactivation of uplink and downlink PDCP duplication functions, theactivation of an uplink PDCP duplication function, the activation of adownlink PDCP duplication function or the activation of PDCP duplicationfunction in a default direction (in uplink, in downlink or in bothuplink and downlink). Here, the activation order is not restricted. Itis possible to activate the PDCP duplication function on the gNB-DUside, followed by the PDCP duplication function on the UE side; or, itis possible to activate the PDCP duplication function on the UE side,followed by the PDCP duplication function on the gNB-DU side; or, it isalso possible to simultaneously activate the PDCP duplication functionon the gNB-DU side and the PDCP duplication function on the UE side. Inaddition, optionally, upon receiving the activation informationtransmitted by the gNB-CU, the gNB-DU may reply whether the activationis successful. If the activation being successful is replied, the PDCPduplication function on the gNB-DU side is activated; or otherwise, thePDCP duplication function on the gNB-DU side is not activated. Further,after the PDCP duplication function is activated, the gNB-CU may alsotransmit deactivation information to the gNB-DU and/or the UE.Optionally, the gNB-DU may reply whether the deactivation is successful.If the deactivation is successful, the PDCP duplication function isstopped on the gNB-DU side; or otherwise, the PDCP duplication functionis used continuously.

Way 2: The gNB-DU activates the PDCP duplication function of the dataradio bearer on the UE side. The gNB-DU transmits PDCP duplicationfunction activation information to a UE. Then, the PDCP duplicationfunction of the data radio bearer is activated on the UE side, and dataof the data radio bearer will be transmitted according to the receivedRRC configuration message.

It is indicated that the PDCP duplication function of the data radiobearer has been activated on the gNB-DU side and the UE side, if thestep C has been executed, and step D will be executed. There are twopossibilities, if the step C has not been executed: 1) after the steps Aand B have ended, the PDCP duplication function of the data radio bearerhas been activated on the gNB-DU side and the UE side (the activation onthe UE side has been realized by an individual signaling), and step Dwill be executed in this case; and, 2) after the steps A and B haveended, the configuration of the PDCP duplication function has beencompleted on the gNB-DU side and the UE side but this function has notbeen activated, and step E will be executed in this case.

Step D: Data of the data radio bearer having the activated PDCPduplication function is transmitted. This step is performed after thePDCP duplication function of the data radio bearer has been activated(that is, data of the data radio bearer will be transmitted between thegNB-DU and the UE according to the configuration of the correspondingPDCP duplication function). This step includes the following substeps,if the data radio bearer is downlink.

Substep D-a (downlink): The gNB-CU generates PDCP PDUs of the data radiobearer, but does not duplicate each PDCP PDU.

Substep D-b (downlink): The PDCP PDUs obtained in the substep D-a(downlink) are transmitted to the gNB-DU through a tunnel on the F1interface. In another way, for the data radio bearer supporting the PDCPduplication function, its data can be transmitted on the F1 interface byan SCTP/RUDP (Reliable UDP) protocol, or transmitted by a control planemessage of the F1 interface.

Substep D-c (downlink): The gNB-DU duplicates each received PDCP PDU toobtain two identical PDCP PDUs and then transmits the two identical PDCPPDUs to two different RLC entities (e.g., RLC 1 and RLC2), respectively,or the gNB-DU transmits each received PDCP PDU for two times to twodifferent RLC entities (e.g., RLC1 and RLC2); then, the two identicalPDCP PDUs are transmitted to an MAC layer through two different logicchannels (e.g., a logic channel 1 and a logic channel 2); and, the MAClayer transmits, by physical layers of two different cells, the datafrom the two different logic channels to two different cells (e.g., acell 1 and a cell 2, where the two cells may be at different frequenciesor at identical frequencies).

This step includes the following substeps, if the data radio bearer isuplink.

Substep D-a (uplink): The gNB-DU receives data from two different cells(e.g., a cell 1 and a cell 2, where the two cells may be at differentfrequencies or at identical frequencies), and the data from the twodifferent cells are processed by a physical layer and an MAC layer andthen transmitted to two different RLC entities (e.g., RLC 1 and RLC2)via two different logic channels (e.g., a logic channel 1 and a logicchannel 2), respectively.

Substep D-b (uplink): The data processed by the two RLC entities will betransmitted to the gNB-CU through a tunnel on the F1 interface; or, onePDCP PDU is discarded, and the remaining PDCP PDU is transmitted to thegNB-CU through a tunnel on the F1 interface, if the gNB-DU finds twoidentical PDCP PDUs in the data output from the RLC entities (the gNB-DUcan identify whether two PDCP PDUs output from the RLC entities areidentical).

Substep D-c (uplink): The gNB-CU processes the received PDCP PDUs (e.g.,discarding the duplicated PDCP PDU) by a PDCP layer to obtain a PDCPSDU.

Step E: Data of the data radio bearer configured with the PDCPduplication function which has not been activated is transmitted. Forthe downlink data transmission, implementations may be as follows.

Way 1: The gNB-CU transmits, by a tunnel on the F1 interface, a PDCP PDUof the data radio bearer to the gNB-DU, the gNB-DU transmits the PDU tothe specified RLC entity (e.g., the main RLC entity or default RLCentity), and the PDCP PDU is transmitted to an MAC layer via a logicchannel corresponding to the specified RLC entity and then transmittedto a user via a cell, if an RLC entity (e.g., the main RLC entity ordefault RLC entity) to be used when the PDCP duplication function isconfigured but not activated has been specified in the step A and/or B.

Way 2: The gNB-CU transmits a PDCP PDU of the data radio bearer to thegNB-DU through a tunnel, the gNB-DU autonomously selects a configuredRLC entity, and the PDCP PDU is transmitted to an MAC layer via a logicchannel corresponding to this RLC entity and then transmitted to a uservia a cell, if an RLC entity to be used when the PDCP duplicationfunction is configured but not activated has not been specified in thestep A and/or B.

For the uplink data transmission, implementations may be as follows.

Way 1: The gNB-DU transmits, via a specified logic channel (thespecified logic channel corresponds to the specified RLC entity) and tothe specified RLC entity (e.g., the main RLC entity or default RLCentity), the data of the data radio bearer which is received from a celland processed by a physical layer and an MAC layer, and the processedPDCP PDU is transmitted to the gNB-CU by a tunnel on the F1 interfaceand then processed by a PDCP layer to obtain a PDCP SDU, if an RLCentity (e.g., the main RLC entity or default RLC entity) to be used whenthe PDCP duplication function is configured but not activated has beenspecified in the step A and/or B.

Way 2: The gNB-DU transmits, via a logic channel and to a correspondingRLC entity (the logic channel and the RLC entity are autonomouslydetermined by the gNB-DU), the data of the data radio bearer which isreceived from a cell and processed by a physical layer and an MAC layer,and the processed PDCP PDU is transmitted to the gNB-CU through a tunnelon the F1 interface by the gNB-DU and then processed by a PDCP layer toobtain a PDCP SDU, if an RLC entity to be used when the PDCP duplicationfunction is configured but not activated has not been specified in thestep A and/or B.

The message names in the steps A and B are merely exemplary, and theinvolved configuration information may be carried in other messages fortransmission, for example, a UE context setup request and a UE contextsetup response, a bearer setup request and a bearer setup response, a DLRRC message transfer and a UL RRC message transfer, or the like.

In addition, the existing configuration of the data radio bearer can bemodified by the steps A and B. In order to improve the reliability ofdata transmission of this data radio bearer, it is required to configurethe data radio bearer as a data radio bearer supporting the PDCPduplication function, if the data radio bearer has been configured as anordinary bearer which does not support the PDCP duplication function. Inthis case, the configuration of this data radio bearer can be modifiedby the steps A and B, that is, the configuration messages in the steps Aand B are transmitted by a bearer modification request and a bearermodification response. In another way, in the steps A and B, only thenewly added information or the configuration information to be modifiedis contained. For example, when this data radio bearer does not supportthe PDCP duplication function, the following information has beenconfigured:

configuration information of the RLC entity 1;

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 1; and

gNB-CU side and gNB-DU side tunnel information of a tunnel on the F1interface established for the data radio bearer.

When the data radio bearer will be configured as a data radio bearersupporting the PDCP duplication function, based on the existingconfiguration information, the modified existing configurationinformation and the newly added information will be transmitted to thegNB-DU in the step A. For example, the modified existing configurationinformation includes:

updated part of the configuration information of the RLC entity 1, forexample, added indication information for indicating whether the entityis a main RLC entity; and

updated part of the configuration information of the logic channelcorresponding to the RLC entity 1, for example, added restrictioninformation for mapping the logic channel.

The newly added information includes:

configuration information of the RLC entity 2; and

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 2.

In this embodiment, a Signaling Radio Bearer (SRB, e.g., SRB1/SRB1S,SRB2/SRB2S, SRB3 and the like) is configured with a PDCP duplicationfunction, and in a gNB-DU, two RLC entities and a logic channelidentifier and/or configuration corresponding to each RLC entity areconfigured for the signaling radio bearer. For downlink transmission, aPDCP layer on a gNB-CU duplicates each PDCP PDU of the signaling radiobearer to obtain two identical PDCP PDUs or transmits each PDPC PUD fortwo times to obtain two identical PDCP PDUs, and the two identical PDCPPDUs are transmitted to the gNB-DU by the F1 control plane message (F1-Cmessage); and, the gNB-DU transmits, to two configured RLC entities, thereceived two identical PDCP PDUs of a same signaling radio bearer. Inthis embodiment, the method includes the following steps.

Step A: A gNB-CU transmits, to a gNB-DU, a request message ofconfiguring a signaling radio bearer supporting a PDCP duplicationfunction, wherein the message at least contains one or more pieces ofthe following information.

1) Information indicating the support of the PDCP duplication function,wherein possible implementations are as follows:

way 1: indication information of supporting the PDCP duplicationfunction, wherein the indication information indicates that thesignaling radio bearer supports the PDCP duplication function;

way 2: type information of the signaling radio bearer, wherein the typeinformation indicates that the signaling radio bearer is a signalingradio bearer supporting the PDCP duplication function; and

way 3: identifier information of the signaling radio bearer, wherein oneor more identifiers of the signaling radio bearer supporting the PDCPduplication function are predefined or preconfigured, and the signalingradio bearer supports the PDCP duplication function if the identifier ofthe signaling radio bearer indicates that the signaling radio bearer isa signaling radio bearer supporting the PDCP duplication function.

Further, the information indicating the support of the PDCP duplicationfunction may further include indication information of uplink/downlink.The indication information indicates the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function indownlink, or the support of the PDCP duplication function in both uplinkand the downlink. If the indication information of uplink/downlink isnot included, the information indicating the support of the PDCPduplication function may indicate the support of the PDCP duplicationfunction in both uplink and downlink, the support of the PDCPduplication function in downlink, the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function in adefault direction (in uplink, in downlink or in both uplink anddownlink).

2) Part or all of configuration information of at least one RLC entitycorresponding to the signaling radio bearer. The signaling radio bearersupporting the PDCP duplication function will have two RLC entities, butthe configuration information can contain part or all of configurationinformation of one RLC entity or contain part or all of configurationinformation of two RLC entities (it is indicated that the configurationinformation not contained in the configuration message can reuse theexisting configuration, if only part of configuration information iscontained in the configuration information). For example, in a situationwhere the configuration information of one RLC entity is contained, itis indicated that the existing configuration information of the RLCentity of the signaling radio bearer can be reused and the containedconfiguration information of the RLC entity is specific to a newly addedRLC entity. In a situation where the configuration information of twoRLC entities is contained, the newly received configuration informationof the two RLC entities can cover the existing information, if thegNB-DU already has configuration information of at least one RLC entityof the signaling radio bearer; and, the gNB-DU directly uses the newlyreceived configuration information of the two RLC entities, if thegNB-DU does not have any information of RLC entities corresponding tothe signaling radio bearer. In addition, the configuration informationof each RLC entity may contain indication information for indicatingwhether the RLC entity is a main RLC entity (or referred to as a defaultRLC entity) (it is possible to not contain the indication information,if an RLC entity is not configured as a main RLC entity; in another way,a main RLC entity does not contain indication information, while anon-main RLC entity will contain one piece of indication information toindicate that this RLC entity is a non-main RLC entity). The indicationinformation may be optional or mandatory. The indication information hasthe following functions: for the downlink data transmission, theindication message is used for indicating how the gNB-DU distributes thereceived PDCP PDU to two RLC entities configured for the signaling radiobearer; while for the uplink data transmission, the indication messageis used for indicating how the gNB-DU distributes, to two RLC entitiesconfigured for the signaling radio bearer, data of the signaling radiobearer received from different cells. The indication information canindicate a RLC entity (e.g., a main RLC entity) to be used by the gNB-DUwhen only one RLC entity needs to be used. For example, for downlinkdata, the PDCP PDU of the signaling radio bearer received from thegNB-CU is transmitted to only the main RLC entity, if an RLC entity isindicated as a main RLC entity, and when the signaling radio bearer isconfigured to support a PDCP duplication function and this function hasnot been activated; while for uplink data, all data of the signalingradio bearer received by the gNB-DU is transmitted to the main RLCentity. For another example, when the signaling radio bearer isconfigured to support a PDCP duplication function and this function hasbeen activated, for downlink data, the gNB-DU transmits the PDCP PDU tothe main RLC entity, if the gNB-DU receives a PDCP PDU of the signalingradio bearer from the gNB-CU for the first time; and the gNB-DUtransmits the PDCP PDU to the other RLC entity (the non-main RLCentity), if the gNB-DU receives a PDCP PDU of the signaling radio bearerfrom the gNB-CU for the second time.

3) Identifier information and/or configuration information of a logicchannel corresponding to at least one configured RLC entity for thesignaling radio bearer, wherein the configuration information containsrestriction information for mapping the logic channel to indicate thatthe data of this logic channel can be transmitted to only a cell or acarrier indicated by the restriction information; or, restrictioninformation of a mapping corresponding to at least one configured RLCentity, for example, data from an RLC entity 1 being transmitted to acell 1 or a carrier 1 indicated by the restriction information, datafrom an RLC entity 2 being transmitted to a cell 2 or a carrier 2indicated by the restriction information.

4) Indication information for assisting the gNB-DU in identifyingwhether to transmit PDCP PDUs of a same signaling radio bearer todifferent RLC entities, wherein the indication information indicates thegNB-DU that two PDCP PDUs of the signaling radio bearer received fromthe F1 interface should be transmitted to different RLC entities.

Step B: The gNB-DU executes the related configuration, and the gNB-DUfeeds back, to the gNB-CU, a response message of configuring thesignaling radio bearer supporting the PDCP duplication function in orderto indicate whether the gNB-DU accepts the configuration of thesignaling radio bearer in the step A, if the gNB-DU accepts theconfiguration of the signaling radio bearer in the step A. This responsemessage is optional.

Step C: The PDCP duplication function is activated. This step isoptional. This step includes activation of the PDCP duplication functionon the gNB-CU side, the gNB-DU side and the UE side. Possibleimplementations are as follows.

Way 1: The gNB-CU activates the PDCP duplication function of thesignaling radio bearer on the gNB-DU side and/or the UE side. The gNB-CUtransmits PDCP duplication function activation information to the gNB-DUand/or a UE. Then, the PDCP duplication function of the signaling radiobearer is activated on the gNB-DU side, and data of the signaling radiobearer will be transmitted according to the configuration information inthe steps A and B; and, the PDCP duplication function of the signalingradio bearer is also activated on the UE side, and data of the signalingradio bearer will be transmitted according to the received RRCconfiguration message. Further, the activation information may indicatethe activation of an uplink PDCP duplication function, the activation ofa downlink PDCP duplication function or the activation of uplink anddownlink PDCP duplication functions. If there is no indicationinformation in the activation information, the activation informationindicates the activation of uplink and downlink PDCP duplicationfunctions, the activation of an uplink PDCP duplication function, theactivation of a downlink PDCP duplication function or the activation ofPDCP duplication function in a default direction (in uplink, in downlinkor in both uplink and downlink). Here, the activation order is notrestricted. It is possible to activate the PDCP duplication function onthe gNB-DU side, followed by the PDCP duplication function on the UEside; or, it is possible to activate the PDCP duplication function onthe UE side, followed by the PDCP duplication function on the gNB-DUside; or, it is also possible to simultaneously activate the PDCPduplication function on the gNB-DU side and the PDCP duplicationfunction on the UE side. In addition, optionally, upon receiving theactivation information transmitted by the gNB-CU, the gNB-DU may replywhether the activation is successful. If the activation being successfulis replied, the PDCP duplication function on the gNB-DU side isactivated; or otherwise, the PDCP duplication function on the gNB-DUside is not activated. Further, after the PDCP duplication function isactivated, the gNB-CU may also transmit deactivation information to thegNB-DU and/or the UE. Optionally, the gNB-DU may reply whether thedeactivation is successful. If the deactivation being successful isreplied, the PDCP duplication function is stopped on the gNB-DU side; orotherwise, the PDCP duplication function is used continuously.

Way 2: The gNB-DU activates the PDCP duplication function of thesignaling radio bearer on the gNB-CU side and/or the UE side. The gNB-DUtransmits PDCP duplication function activation information to the gNB-CUand/or the UE. Then, the PDCP duplication function of the signalingradio bearer is activated on the gNB-CU side, and data of the signalingradio bearer will be transmitted according to the configurationinformation in the steps A and B (a duplicated PDCP PDU is transmittedto the gNB-DU through the F1 interface or a duplicated PDCP PDUtransmitted by the gNB-DU is received through the F1 interface); and,the PDCP duplication function of the signaling radio bearer is alsoactivated on the UE side, and data of the signaling radio bearer will betransmitted according to the received RRC configuration information.Further, the activation information may indicate the activation of anuplink PDCP duplication function, the activation of a downlink PDCPduplication function or the activation of uplink and downlink PDCPduplication functions. If there is no indication information in theactivation information, the activation information indicates theactivation of uplink and downlink PDCP duplication functions, theactivation of an uplink PDCP duplication function, the activation of adownlink PDCP duplication function or the activation of PDCP duplicationfunction in a default direction (in uplink, in downlink or in bothuplink and downlink). Here, the activation order is not restricted. Itis possible to activate the PDCP duplication function on the gNB-CUside, followed by the PDCP duplication function on the UE side; or, itis possible to activate the PDCP duplication function on the UE side,followed by the PDCP duplication function on the gNB-CU side; or, it isalso possible to simultaneously activate the PDCP duplication functionon the gNB-CU side and the PDCP duplication function on the UE side. Inaddition, optionally, upon receiving the activation informationtransmitted by the gNB-DU, the gNB-CU may reply whether the activationis successful. If the activation being successful is replied, the PDCPduplication function on the gNB-CU side is activated; or otherwise, thePDCP duplication function on the gNB-CU side is not activated. Further,after the PDCP duplication function is activated, the gNB-DU may alsotransmit deactivation information to the gNB-CU and/or the UE.Optionally, the gNB-CU may reply whether the deactivation is successful.If the deactivation being successful is replied, the PDCP duplicationfunction is stopped on the gNB-CU side; or otherwise, the PDCPduplication function is used continuously.

It is indicated that the PDCP duplication function of the signalingradio bearer has been activated on the gNB-CU side, the gNB-DU side andthe UE side, if the step C has been executed, and step D will beexecuted. There are two possibilities, if the step C has not beenexecuted: 1) after the steps A and B have ended, the PDCP duplicationfunction of the signaling radio bearer has been activated on the gNB-CUside, the gNB-DU side and the UE side (the activation on the UE side hasbeen realized by an individual signaling), and step D will be executedin this case; and, 2) after the steps A and B have ended, theconfiguration of the PDCP duplication function has been completed ongNB-CU side, the gNB-DU side and the UE side but this function has notbeen activated, and step E will be executed in this case.

Step D: Data of the signaling radio bearer having the activated PDCPduplication function is transmitted by an F1-C message. This step isperformed after the PDCP duplication function of the signaling radiobearer has been activated (that is, data of the signaling radio bearerwill be transmitted among the gNB-CU, the gNB-DU and the UE according tothe configuration of the corresponding PDCP duplication function). thisstep includes the following substeps, if the signaling radio bearer isdownlink.

Substep D-a (downlink): The gNB-CU duplicates a PDCP PDU of thesignaling radio bearer to obtain two identical PDCP PDUs or transmits aPDCP PDU of the signaling radio bearer for two times to obtain twoidentical PDCP PDUs.

Substep D-b (downlink): The two identical PDCP PDUs obtained in thesubstep D-a (downlink) are transmitted to the gNB-DU by a control planemessage on the F1 interface (an F1-C message). Possible implementationsare as follows.

Way 1: The two identical PDCP PDUs of the signaling radio bearer arecarried in an F1-C message (e.g., RRC MESSAGE TRANSFER). Optionally, theF1-C message further indicates the gNB-DU to transmit the two PDCP PDUsto different RLC entities or transmit the two PDCP PDUs by differentlogic channels or transmit the two PDCP PDUs by different cells, orindicates the gNB-DU to respectively transmit the two PDCP PDUs tospecified RLC entities or transmit the two PDCP PDUs by specified logicchannels or transmit the two PDCP PDUs by specified cells.

Way 2: The two identical PDCP PDUs of the signaling radio bearer arecarried in two F1-C messages (e.g., RRC MESSAGE TRANSFER). Each messagecontains a piece of indication information for assisting the gNB-DU inidentifying that the PDCP PDUs from the two F1-C messages should betransmitted to different RLC entities. For example, the indicationinformation contained in each F1-C message indicates that the PDCP PDUof the signaling radio bearer contained in this F1-C message should betransmitted to which RLC entity or transmitted by which logic channel ortransmitted by which cell, or indicates whether the PDCP PDU of thesignaling radio bearer contained in this F1-C message is a duplicatedPDU (a non-original PDCP PDU), or indicates whether the PDCP PDU of thesignaling radio bearer contained in this F1-C message is an originalPDCP PDU (a non-duplicated PDCP PDU); or, two pieces of indicationinformation contained in the two F1-C messages indicate that the PDCPPDUs of the signaling radio bearer contained in the two F1-C messagesshould be transmitted to different RLC entities. As anotherimplementation, one piece of indication information for assisting inidentifying whether the PDCP PDU of the signaling radio bearer containedin one message is identical to the PDCP PDU of the same signaling radiobearer contained in the other message is added into each F1-C message.Possible indications are as follows: a sequence number is assigned tothe PDCP PDU of a signaling radio bearer contained in each F1-C message;it is indicated that the two PDCP PDUs contained in the two messages aretwo identical PDUs of a same signaling radio bearer, if a same sequencenumber is contained in the two messages; or, it is indicated that thetwo PDCP PDUs contained in the two messages are two identical PDUs of asame signaling radio bearer, if there are two F1-C messages, one ofwhich contains an odd number (or an even number) while the other one ofwhich contains an even number (or an odd number) that is 1 greater thanthe odd number (or the even number). As still another implementation, anew F1-C message is defined. This message is specially used fortransmitting duplicated PDCP PDUs. For example, an original PDCP PDUwill be transmitted for two times after it has been duplicated,specifically, the original PDCP PDU is transmitted on the F1 interfaceby the RRC MESSAGE TRANSFER for one time, and the original PDCP PDU istransmitted by the newly defined F1-C message (e.g., RRC MESSAGE COPYTRANSFER) for another time. In this way, in the gNB-DU, the PDCP PDUstransmitted by the RRC MESSAGE TRANSFER and the RRC MESSAGE COPYTRANSFER need to be transmitted by different RLC entities and differentcells.

Substep D-c (downlink): The gNB-DU transmits the received two identicalPDCP PDUs of the same signaling radio bearer to two different RLCentities (e.g., RLC1 and RLC2), the two identical PDCP PDUs are thentransmitted to an MAC layer by a logic channel or two different logicchannels (e.g., a logic channel 1 and a logic channel 2), and the MAClayer transmits, by physical layers of two different cells, data from alogic channel or the two different logic channels to two different cells(e.g., a cell 1 and a cell 2, where the two cells may be at differentfrequencies or at identical frequencies), respectively. In this step,the gNB-DU may receive two identical PDCP PDUs of a same signaling radiobearer. On how the gNB-DU distributes the received data to two RLCentities, possible implementations are as follows.

Way 1: The implementation is determined by gNB-DU according to theexisting configuration. For example, the gNB-DU transmits the receivedPDCP PDUs of the signaling radio bearer to a specific RLC entity, ortransmits the received PDCP PDUs by a specified logic channel, ortransmits the received PDCP PDUs to a specified cell, according to theindication message in the F1-C message in the substep D-b (downlink). Asanother example, for two identical PDCP PDUs, the first received PDUwill be transmitted to a specific RLC entity (e.g., RLC1) by the gNB-DU,wherein the specific RLC entity may be the configured main RLC entity(or the default RLC entity); while the second received PDU will betransmitted to the other RLC entity (the non-main RLC entity) by thegNB-DU.

Way 2: The implementation is set by the gNB-DU autonomously. As animplementation, the gNB-DU autonomously transmits the two PDCP PDUs totwo different RLC entities, if the gNB-DU has identified that the twoPDCP PDUs of the signaling radio bearer need to be transmitted todifferent RLC entities. As another implementation, for two identicalPDCP PDUs, the first received PDCP PDU is transmitted to the RLC1, andthe second received PDCP PDU is transmitted to the RLC2. As stillanother implementation, once the gNB-DU receives a data packet (e.g.,PDCP PDU1), the gNB-DU autonomously duplicates this data packet toobtain two identical data packets and then transmits the two identicaldata packets to two RLC entities (RLC1 and RLC2), respectively, or thegNB-DU transmits this data packet for two times to obtain two identicaldata packets and then transmits the two identical data packets to twodifferent RLC entities, respectively. Hereafter, the gNB-DU may discardthis data packet since this data packet has been transmitted todifferent RLC entities, if the gNB-DU receives an identical data packet(e.g., PDCP PDU1) again; or, the gNB-DU may duplicate this data packetto obtain two identical data packets and then transmit the two identicaldata packets to two RLC entities (RLC1 and RLC2), respectively, or maytransmit this data packet for two times to obtain two identical datapackets and then transmit the two identical data packets to twodifferent RLC entities, respectively.

This step includes the following substeps, if the signaling radio beareris uplink.

Substep D-a (uplink): The gNB-DU receives data from two different cells(e.g., a cell 1 and a cell 2, where the two cells may be at differentfrequencies or at identical frequencies) respectively, and the data fromthe two different cells are processed by a physical layer and an MAClayer and then transmitted to two different RLC entities (e.g., RLC1 andRLC2) by a logic channel or two different logic channels (e.g., a logicchannel 1 and a logic channel 2), respectively.

Substep D-b (uplink): The data processed by the two RLC entities will betransmitted to the gNB-CU by an F1-C message (the data may be carried ina same F1-C message or carried in different F1-C message; or, it is alsopossible to discard one of two identical PDCP PDUs and transmit theremaining PDCP PDU to the gNB-CU by an F1-C message).

Substep D-c (uplink): The gNB-CU processes the received PDCP PDUs (e.g.,discards a duplicated PDCP PDU) by a PDCP layer to obtain a PDCP SDU.

Step E: Data of the signaling radio bearer configured with the PDCPduplication function which has not been activated is transmitted. Forthe downlink data transmission, implementations may be as follows.

Way 1: The gNB-CU transmits, by an F1-C message, a PDCP PDU of thesignaling radio bearer to the specified RLC entity (e.g., the main RLCentity or default RLC entity), and the PDCP PDU is transmitted to an MAClayer via a logic channel corresponding to the specified RLC entity andthen transmitted to a user via a cell, if an RLC entity (e.g., the mainRLC entity or default RLC entity) to be used when the PDCP duplicationfunction is configured but not activated has been specified in the stepA and/or B.

Way 2: The gNB-CU transmits a PDCP PDU of the signaling radio bearer tothe gNB-DU by an F1-C message, the gNB-DU autonomously selects aconfigured RLC entity, and the PDCP PDU is transmitted to an MAC layervia a logic channel corresponding to this RLC entity and thentransmitted to a user via a cell, if an RLC entity to be used when thePDCP duplication function is configured but not activated has not beenspecified in the step A and/or B.

For the uplink data transmission, implementations may be as follows.

Way 1: The gNB-DU transmits, via a specified logic channel (thespecified logic channel corresponds to the specified RLC entity) and tothe specified RLC entity (e.g., the main RLC entity or default RLCentity), the data of the signaling radio bearer which is received from acell and processed by a physical layer and an MAC layer, and theprocessed PDCP PDU is transmitted to the gNB-CU by an F1-C message andthen processed by a PDCP layer to obtain a PDCP SDU, if an RLC entity(e.g., the main RLC entity or default RLC entity) to be used when thePDCP duplication function is configured but not activated has beenspecified in the step A and/or B.

Way 2: The gNB-DU transmits, via a logic channel and to a correspondingRLC entity (the logic channel and the RLC entity are autonomouslydetermined by the gNB-DU), the data of the signaling radio bearer whichis received from a cell and processed by a physical layer and an MAClayer, and the processed PDCP PDU is transmitted to the gNB-CU throughan F1-C message by the gNB-DU and then processed by a PDCP layer toobtain a PDCP SDU, if an RLC entity to be used when the PDCP duplicationfunction is configured but not activated has not been specified in thestep A and/or B.

The message names in the steps A and B are merely exemplary, and may beother messages as well.

In addition, the existing configuration of the signaling radio bearercan be modified by the steps A and B. In order to improve thereliability of data transmission of this signaling radio bearer, it isrequired to configure the signaling radio bearer as a signaling radiobearer supporting the PDCP duplication function, if the signaling radiobearer has been configured as an ordinary bearer which does not supportthe PDCP duplication function. In this case, the configuration of thissignaling radio bearer can be modified by the steps A and B. In anotherway, in the steps A and B, only the newly added information or theconfiguration information to be modified is contained. For example, whenthis signaling radio bearer does not support the PDCP duplicationfunction, the following information has been configured:

configuration information of the RLC entity 1; and

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 1.

When the signaling radio bearer will be configured as a signaling radiobearer supporting the PDCP duplication function, based on the existingconfiguration information, the modified existing configurationinformation and the newly added information will be transmitted to thegNB-DU in the step A. For example, the modified existing configurationinformation includes: updated part of the configuration information ofthe RLC entity 1, for example, added indication information forindicating whether the entity is a main RLC entity; and

updated part of the configuration information of the logic channelcorresponding to the RLC entity 1, for example, added restrictioninformation for mapping the logic channel.

The newly added information includes:

configuration information of the RLC entity 2; and

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 2.

In this embodiment, a Signaling Radio Bearer (SRB, e.g., SRB1/SRB1S,SRB2/SRB2S, SRB3 and the like) is configured with a PDCP duplicationfunction, and in a DU, two RLC entities and an identifier and/orconfiguration of a logic channel corresponding to each RLC entity areconfigured for this signaling radio bearer. For downlink transmission, aCU transmits each PDCP PDU of the signaling radio bearer to the DUthrough an F1 control plane message (the CU does not duplicate the PDCPPDU), and the DU duplicates the received PDCP PDU of the signaling radiobearer and then transmits the PDCP PDU to the two configured RLCentities, or transmits the PDCP PDU for the two times to the twoconfigured RLC entities respectively. In this embodiment, the methodincludes the following steps.

Step A: A gNB-CU transmits, to a gNB-DU, a request message ofconfiguring a signaling radio bearer supporting a PDCP duplicationfunction, wherein the message at least contains one or more pieces ofthe following information.

1) Information indicating the support of the PDCP duplication function,wherein possible implementations are as follows:

way 1: indication information of supporting the PDCP duplicationfunction, wherein the indication information indicates that thesignaling radio bearer supports the PDCP duplication function;

way 2: type information of the signaling radio bearer, wherein the typeinformation indicates that the signaling radio bearer is a signalingradio bearer supporting the PDCP duplication function; and

way 3: identifier information of the signaling radio bearer, wherein oneor more identifiers of the signaling radio bearer supporting the PDCPduplication function are predefined or preconfigured, and the signalingradio bearer supports the PDCP duplication function if the identifier ofthe signaling radio bearer indicates that the signaling radio bearer isa signaling radio bearer supporting the PDCP duplication function.

Further, the information indicating the support of the PDCP duplicationfunction may further include indication information of uplink/downlink.The indication information indicates the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function indownlink, or the support of the PDCP duplication function in both uplinkand the downlink. If the indication information of uplink/downlink isnot included, the information indicating the support of the PDCPduplication function may indicate the support of the PDCP duplicationfunction in both uplink and downlink, the support of the PDCPduplication function in downlink, the support of the PDCP duplicationfunction in uplink, or the support of the PDCP duplication function in adefault direction (in uplink, in downlink or in both uplink anddownlink).

2) Part or all of configuration information of at least one RLC entitycorresponding to the signaling radio bearer. The signaling radio bearersupporting the PDCP duplication function will have two RLC entities, butthe configuration message can contain part or all of configurationinformation of one RLC entity or contain part or all of configurationinformation of two RLC entities (it is indicated that the configurationinformation not contained in the configuration message can reuse theexisting configuration, if only part of configuration information iscontained in the configuration message). For example, in a situationwhere the configuration information of one RLC entity is contained, itis indicated that the existing configuration information of the RLCentity of the signaling radio bearer can be reused and the containedconfiguration information of the RLC entity is specific to a newly addedRLC entity. In a situation where the configuration information of twoRLC entities is contained, the newly received configuration informationof the two RLC entities can cover the existing information, if thegNB-DU already has configuration information of at least one RLC entityof the signaling radio bearer; and, the gNB-DU directly uses the newlyreceived configuration information of the two RLC entities, if thegNB-DU does not have any information of RLC entities corresponding tothe signaling radio bearer. In addition, the configuration informationof each RLC entity may contain indication information for indicatingwhether the RLC entity is a main RLC entity (or referred to as a defaultRLC entity) (it is possible to not contain the indication information,if an RLC entity is not configured as a main RLC entity; in another way,a main RLC entity does not contain indication information, while anon-main RLC entity will contain one piece of indication information forindicating that this RLC entity is a non-main RLC entity). Theindication information may be optional or mandatory. The indicationinformation has the following functions: for the downlink datatransmission, the indication message is used for indicating how thegNB-DU distributes the received PDCP PDU to two RLC entities configuredfor the signaling radio bearer; while for the uplink data transmission,the indication message is used for indicating how the gNB-DUdistributes, to two RLC entities configured for the signaling radiobearer, data belonging to the signaling radio bearer received fromdifferent cells. The indication information can indicate a RLC entity(e.g., a main RLC entity) to be used by the gNB-DU when only one RLCentity needs to be used. For example, for downlink data, the PDCP PDUbelonging to the signaling radio bearer received from the gNB-CU istransmitted to only the main RLC entity, if an RLC entity is indicatedas a main RLC entity, and when the signaling radio bearer is configuredto support a PDCP duplication function and this function has not beenactivated; while for uplink data, all data belonging to the signalingradio bearer received by the gNB-DU is transmitted to the main RLCentity. For another example, when the signaling radio bearer isconfigured to support a PDCP duplication function and this function hasbeen activated, for downlink data, the gNB-DU transmits the PDCP PDU tothe main RLC entity, if the gNB-DU receives a PDCP PDU belonging to thesignaling radio bearer from the gNB-CU for the first time; and thegNB-DU transmits the PDCP PDU to the other RLC entity (the non-main RLCentity), if the gNB-DU receives a PDCP PDU belonging to the signalingradio bearer from the gNB-CU for the second time.

3) Identifier information and/or configuration information of a logicchannel corresponding to at least one configured RLC entity for thesignaling radio bearer, wherein the configuration information containsrestriction information for mapping the logic channel to indicate thatthe data of this logic channel can be transmitted to only a cell or acarrier indicated by the restriction information; or, restrictioninformation of a mapping corresponding to at least one configured RLCentity, for example, data from an RLC entity 1 being transmitted to acell 1 or a carrier 1 indicated by the restriction information, datafrom an RLC entity 2 being transmitted to a cell 2 or a carrier 2indicated by the restriction information.

Step B: The gNB-DU executes the related configuration, and the gNB-DUfeeds back, to the gNB-CU, a response message of configuring thesignaling radio bearer supporting the PDCP duplication function in orderto indicate whether the gNB-DU accepts the configuration of thesignaling radio bearer in the step A, if the gNB-DU accepts theconfiguration of the signaling radio bearer in the step A. This responsemessage is optional.

Step C: The PDCP duplication function is activated. This step isoptional. This step includes activation of the PDCP duplication functionon the gNB-DU side and the UE side. Possible implementations are asfollows.

Way 1: The gNB-CU activates the PDCP duplication function of thesignaling radio bearer on the gNB-DU side and/or the UE side. The gNB-CUtransmits PDCP duplication function activation information to the gNB-DUand/or a UE. Then, the PDCP duplication function of the signaling radiobearer is activated on the gNB-DU side, and data of the signaling radiobearer will be transmitted according to the configuration information inthe steps A and B; and, the PDCP duplication function of the signalingradio bearer is also activated on the UE side, and data of the signalingradio bearer will be transmitted according to the received RRCconfiguration message. Further, the activation information may indicatethe activation of an uplink PDCP duplication function, the activation ofa downlink PDCP duplication function or the activation of uplink anddownlink PDCPPDCP duplication functions. If there is no indicationinformation in the activation information, the activation informationindicates the activation of uplink and downlink PDCPPDCP duplicationfunctions, the activation of an uplink PDCP duplication function, theactivation of a downlink PDCP duplication function or the activation ofPDCP duplication function in a default direction (in uplink, in downlinkor in both uplink and downlink). Here, the activation order is notrestricted. It is possible to activate the PDCP duplication function onthe gNB-DU side, followed by the PDCP duplication function on the UEside; or, it is possible to activate the PDCP duplication function onthe UE side, followed by the PDCP duplication function on the gNB-DUside; or, it is also possible to simultaneously activate the PDCPduplication function on the gNB-DU side and the PDCP duplicationfunction on the UE side. In addition, optionally, upon receiving theactivation information transmitted by the gNB-CU, the gNB-DU may replywhether the activation is successful. If the activation being successfulis replied, the PDCP duplication function on the gNB-DU side isactivated; or otherwise, the PDCP duplication function on the gNB-DUside is not activated. Further, after the PDCP duplication function isactivated, the gNB-CU may also transmit deactivation information to thegNB-DU and/or the UE. Optionally, the gNB-DU may reply whether thedeactivation is successful. If the deactivation being successful isreplied, the PDCP duplication function is stopped on the gNB-DU side; orotherwise, the PDCP duplication function is used continuously.

Way 2: The gNB-DU activates the PDCP duplication function of thesignaling radio bearer on the UE side. The gNB-DU transmits PDCPduplication function activation information to a UE. Then, the PDCPduplication function of the signaling radio bearer is activated on theUE side, and data of the signaling radio bearer will be transmittedaccording to the received RRC configuration message.

It is indicated that the PDCP duplication function of the signalingradio bearer has been activated on the gNB-DU side and the UE side, ifthe step C has been executed, and step D will be executed. There are twopossibilities, if the step C has not been executed: 1) after the steps Aand B have ended, the PDCP duplication function of the signaling radiobearer has been activated on the gNB-DU side and the UE side (theactivation on the UE side has been realized by an individual signaling),and step D will be executed in this case; and, 2) after the steps A andB have ended, the configuration of the PDCP duplication function hasbeen completed on the gNB-DU side and the UE side but this function hasnot been activated, and step E will be executed in this case.

Step D: Data of the signaling radio bearer having the activated PDCPduplication function is transmitted by an F1-C message. This step isperformed after the PDCP duplication function of the signaling radiobearer has been activated (that is, data of the signaling radio bearerwill be transmitted between the gNB-DU and the UE according to theconfiguration of the corresponding PDCP duplication function). This stepincludes the following substeps, if the signaling radio bearer isdownlink.

Substep D-a (downlink): The gNB-CU generates a PDCP PDU of the signalingradio bearer, but does not duplicate the PDCP PDU.

Substep D-b (downlink): The PDCP PDU obtained in the substep D-a(downlink) is transmitted to the gNB-DU by a control plane message onthe F1 interface (an F1-C message).

Substep D-c (downlink): The gNB-DU duplicates the received PDCP PDU ofthe signaling radio bearer to obtain two identical PDUs and thentransmits the two identical PDCP PDUs to two different RLC entities(e.g., RLC1 and RLC2), or the gNB-DU transmits the PDCP PDU for twotimes to two different RLC entities (e.g., RLC1 and RLC2) respectively;then, the two identical PDCP PDUs are transmitted to an MAC layerthrough a logic channel or two different logic channels (e.g., a logicchannel 1 and a logic channel 2); and, the MAC layer transmits, byphysical layers of two different cells, the data from the logic channelor the two different logic channels to two different cells (e.g., a cell1 and a cell 2, where the two cells may be at different frequencies orat identical frequencies).

This step includes the following substeps, if the signaling radio beareris uplink.

Substep D-a (uplink): The gNB-DU receives data from two different cells(e.g., a cell 1 and a cell 2, where the two cells may be at differentfrequencies or at identical frequencies), and the data are processed bya physical layer and an MAC layer and then transmitted to two differentRLC entities (e.g., RLC1 and RLC2) via a logic channel or two differentlogic channels (e.g., a logic channel 1 and a logic channel 2),respectively.

Substep D-b (uplink): The data processed by the two RLC entities will betransmitted to the gNB-CU by an F1-C message (the data may be carried ina same F1-C message or carried in different F1-C message; or, it is alsopossible to discard one of two identical PDCP PDUs and transmit theremaining PDCP PDU to the gNB-CU by an F1-C message).

Substep D-c (uplink): The gNB-CU processes the received PDCP PDUs (e.g.,discarding a duplicated PDCP PDU) by a PDCP layer to obtain a PDCP SDU.

Step E: Data of the signaling radio bearer configured with the PDCPduplication function which has not been activated is transmitted. Forthe downlink data transmission, implementations may be as follows.

Way 1: The gNB-CU transmits, by an F1-C message, a PDCP PDU of thesignaling radio bearer to the specified RLC entity (e.g., the main RLCentity or default RLC entity), and the PDCP PDU is transmitted to an MAClayer via a logic channel corresponding to the specified RLC entity andthen transmitted to a user via a cell, if an RLC entity (e.g., the mainRLC entity or default RLC entity) to be used when the PDCP duplicationfunction is configured but not activated has been specified in the stepA and/or B.

Way 2: The gNB-CU transmits a PDCP PDU of the signaling radio bearer tothe gNB-DU by an F1-C message, the gNB-DU autonomously selects aconfigured RLC entity, and the PDCP PDU is transmitted to an MAC layervia a logic channel corresponding to this RLC entity and thentransmitted to a user via a cell, if an RLC entity to be used when thePDCP duplication function is configured but not activated has not beenspecified in the step A and/or B. For the uplink data transmission,implementations may be as follows.

Way 1: The gNB-DU transmits, via a specified logic channel (thespecified logic channel corresponds to the specified RLC entity) and tothe specified RLC entity (e.g., the main RLC entity or default RLCentity), the data of the signaling radio bearer which is received from acell and processed by a physical layer and an MAC layer, and theprocessed PDCP PDU is transmitted to the gNB-CU by an F1-C message andthen processed by a PDCP layer to obtain a PDCP SDU, if an RLC entity(e.g., the main RLC entity or default RLC entity) to be used when thePDCP duplication function is configured but not activated has beenspecified in the step A and/or B.

Way 2: The gNB-DU transmits, via a logic channel and to a correspondingRLC entity (the logic channel and the RLC entity are autonomouslydetermined by the gNB-DU), the data of the signaling radio bearer whichis received from a cell and processed by a physical layer and an MAClayer, and the processed PDCP PDU is transmitted to the gNB-CU throughan F1-C message by the gNB-DU and then processed by a PDCP layer toobtain a PDCP SDU, if an RLC entity to be used when the PDCP duplicationfunction is configured but not activated has not been specified in thestep A and/or B.

The message names in the steps A and B are merely exemplary, and may beother messages as well.

In addition, the existing configuration of the signaling radio bearercan be modified by the steps A and B. In order to improve thereliability of data transmission of this signaling radio bearer, it isrequired to configure the signaling radio bearer as a signaling radiobearer supporting the PDCP duplication function, if the signaling radiobearer has been configured as an ordinary bearer which does not supportthe PDCP duplication function. In this case, the configuration of thissignaling radio bearer can be modified by the steps A and B. In anotherway, in the steps A and B, only the newly added information or theconfiguration information to be modified is contained. For example, whenthis signaling radio bearer does not support the PDCP duplicationfunction, the following information has been configured:

configuration information of the RLC entity 1; and

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 1.

When the signaling radio bearer will be configured as a signaling radiobearer supporting the PDCP duplication function, based on the existingconfiguration information, the modified existing configurationinformation and the newly added information will be transmitted to thegNB-DU in the step A. For example, the modified existing configurationinformation includes:

updated part of the configuration information of the RLC entity 1, forexample, added indication information for indicating whether the entityis a main RLC entity; and updated part of the configuration informationof the logic channel corresponding to the RLC entity 1, for example,added restriction information for mapping the logic channel.

the newly added information includes:

configuration information of the RLC entity 2; and

identifier information and/or configuration information of a logicchannel corresponding to the RLC entity 2.

In the present disclosure, by an F1 interface between a gNB-CU and agNB-DU, the transmission of duplicated PDCP PDUs between the gNB-CU andthe gNB-DU is realized, and the reliability of data transmission isimproved.

In the above embodiments, the transmission of a bearer supporting a PDCPduplication function on an F1 interface between a CU and a DU in a basestation is mainly discussed; however, in an actual system, a bearersupporting a PDCP duplication function may also be transmitted on aninterface (e.g., an X2 interface or an Xn interface) between two basestations (e.g., between an eNB and a gNB, between two eNBs, between twogNBs or the like).

For example, for a Data Radio Bearer (DRB) supporting a PDCP duplicationfunction, a PDCP layer for transmitting data of this DRB is located in abase station 1, while other protocol layers (e.g., an RLC layer, an MAClayer and a PHY layer) for transmitting the data of this DRB are locatedin a base station 2. In order to support the transmission of the DRBbetween the base station 1 and the base station 2, the mechanismsdescribed in Embodiments 1 to 3 may be applied between the base station1 and the base station 2 (the interface between the two interfaces maybe an X2 interface or an Xn interface). That is, the gNB-CU in thedescription of Embodiments 1 to 3 is replaced with the base station 1,the gNB-DU in the description of Embodiments 1 to 3 is replaced with thebase station 2, and the F1 interface in the description of Embodiments 1to 3 is replaced with the interface (e.g., an X2 interface or an Xninterface) between the base station 1 and the base station 2.

For example, for a Signaling Radio Bearer (SRB) supporting a PDCPduplication function, a PDCP layer for transmitting data of this SRB islocated in a base station 1, while other protocol layers (e.g., an RLClayer, an MAC layer and a PHY layer) for transmitting the data of thisSRB are located in a base station 2. In order to support thetransmission of the SRB between the base station 1 and the base station2, the mechanisms described in Embodiments 4 to 5 may be applied betweenthe base station 1 and the base station 2 (the interface between the twointerfaces may be an X2 interface or an Xn interface). That is, thegNB-CU in the description of Embodiments 4 to 5 is replaced with thebase station 1, the gNB-DU in the description of Embodiments 4 to 5 isreplaced with the base station 2, and the F1 interface in thedescription of Embodiments 4 to 5 is replaced with the interface (e.g.,an X2 interface or an Xn interface) between the base station 1 and thebase station 2.

The present disclosure further provides a system supporting a PacketData Convergence Protocol (PDCP) duplication function, including a firststation and a second station, or a central unit and a distributed unitin a base station.

The data packet of the radio bearer configured with the PDCP duplicationfunction includes: a data packet of a data radio bearer configured witha PDCP duplication function and/or a data packet of a signaling radiobearer configured with a PDCP duplication function.

The SUL carrier configuration information mentioned in the presentdisclosure includes at least one of:

1. Identification information of a cell where the SUL carrier islocated.

2. Identification information of a base station locating the cell wherethe SUL carrier is located.

3. Basic parameters of the SUL carrier (refer to FrequencyInfoUL inTS38.331), which include at least one of:

1) a carrier frequency of the SUL carrier;

2) a bandwidth of the SUL carrier; and

3) an initial uplink bandwidth portion of the SUL carrier.

4. Signal strength threshold information of the SUL carrier, having thefunction that when a UE initially accesses a cell, if the measuredsignal strength (RSRP) of the cell is lower than the threshold, the UEmay perform a random access process on the SUL carrier to access thecell. Please refer to sul-RSRP-Threshold in TS38.331.

5. Configuration information related to a random access on the SULcarrier, which may be Cell-specific (i.e., cell-specific configurationinformation related to the random access), or UE-specific (i.e.,UE-specific configuration information related to the random access), andmay also include the both. Please refer to RACH-ConfigCommon andRACH-ConfigDedicated in TS38.331.

6. Configuration information of a Physical Uplink Control Channel(PUCCH) on the SUL carrier, which may be Cell-specific (i.e.,cell-specific configuration information related to the PUCCH) orUE-specific (i.e., UE-specific configuration information related to thePUCCH), and may include the both. Please refer to PUCCH-Config inTS38.331.

7. Configuration information of a Physical Uplink Shared Channel (PUSCH)on the SUL carrier, which may be Cell-specific (i.e., cell-specificconfiguration information related to the PUSCH) or UE-specific (i.e.,UE-specific configuration information related to the PUSCH), and mayinclude the both. Please refer to PUSCH-Config in TS38.331.

8. Configuration information of a Sounding Reference Signal (SRS) on theSUL carrier, which may be Cell-specific (i.e., cell-specificconfiguration information related to the SRS) or UE-specific (i.e.,UE-specific configuration information related to the UE), and mayinclude the both. Please refer to SRS-Config in TS38.331.

Referring to FIG. 8, a method for transferring supplemental uplinkcarrier configuration information disclosed in the present disclosureincludes steps of:

Step 101: A first network-side entity acquires SUL carrier configurationinformation;

Step 102: The first network-side entity sends a configuration messagecarrying the SUL carrier configuration information to a secondnetwork-side entity, so that the second network-side entity acquires aresource configuration status of the first network-side entity. Further,the second network-side entity may configure a UE with an SUL carrier.

The method for transferring supplemental uplink carrier configurationinformation disclosed in the present disclosure specifically includestwo aspects:

I. How to exchange the SUL carrier configuration information betweennetwork-side entities (between base stations, or between a central unitand a distributed unit of a base station).

II. How to perform an addition/modification/release of an SUL carrierbetween network-side entities (between base stations, or between acentral unit and a distributed unit of a base station).

The method for transferring configuration optimization informationdisclosed in the present disclosure specifically includes:

III. How the UE reports radio link failure information related to theSUL carrier to the network side entities.

The embodiments of the above three aspects are given as follows,respectively.

I. SUL carrier configuration information is exchanged between two basestations (base station 1 and base station 2), and an interface betweenthe base stations may be X2, Xn, or of other interface type. Pleaserefer to FIG. 9.

Step 1: The base station 1 sends a message 1 (a request message foracquiring an SUL carrier configuration) to the base station 2, themessage 1 including at least one of:

1. Identification information of at least one cell served by the basestation 1.

2. SUL carrier configuration information of the at least one cell servedby the base station 1, the information indicating that the at least onecell served by the base station 1 supports the SUL carrier. If each cellserved by the base station 1 does not support the SUL carrier, theinformation will not be included.

3. Identification information of at least one neighboring cell of the atleast one cell served by the base station 1, namely, the identificationinformation of the at least one neighboring cell, which is a neighboringcell of any cell served by the base station 1.

4. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the base station 1, namely, theSUL carrier configuration information of the at least one neighboringcell, which is a neighboring cell of any cell served by the base station1, the information indicating that the at least one neighboring cell ofthe at least one cell served by the base station 1 supports the SULcarrier. If each neighbor cell of any cell served by the base station 1does not support the SUL carrier, the information will not be included.

5. Identification information of at least one cell served by other basestation.

6. SUL carrier configuration information of the at least one cell servedby the other base station, the information indicating that the at leastone cell served by the other base station supports the SUL carrier. Ifeach cell served by the other base station does not support the SULcarrier, the information will not be included.

7. Identification information of at least one neighboring cell of the atleast one cell served by the other base station, namely, theidentification information of the at least one neighboring cell, whichis a neighboring cell of any cell served by the other base station.

8. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the other base station, namely,the SUL carrier configuration information of the at least oneneighboring cell, which is a neighboring cell of any cell served by theother base station, the information indicating that the at least oneneighbor cell of the at least one cell served by the other base stationsupports the SUL carrier. If each neighboring cell of any cell served bythe base station 1 does not support the SUL carrier, the informationwill not be included.

9. Indication information indicating that the at least one cell servedby the base station 1 supports the SUL carrier.

10. Indication information indicating that the at least one neighboringcell of the at least one cell served by the base station 1 supports theSUL carrier.

11. Indication information indicating that the at least one cell servedby the other base station supports the SUL carrier.

12. Indication information indicating that the at least one neighboringcell of the at least one cell served by the other base station supportsthe SUL carrier.

The information related to the other base station may be transmitted tothe base station 1 from the other base station.

Step 2: The base station 2 sends a message 2 (a configuration messagecarrying SUL carrier configuration information) to the base station 1,the message 2 including at least one of:

1. Identification information of at least one cell served by the basestation 2.

2. SUL carrier configuration information of the at least one cell servedby the base station 2, the information indicating that the at least onecell served by the base station 2 supports the SUL carrier. If each cellserved by the base station 2 does not support the SUL carrier, theinformation will not be included.

3. Identification information of at least one neighboring cell of the atleast one cell served by the base station 2, namely, the identificationinformation of the at least one neighboring cell, which is a neighboringcell of any cell served by the base station 2.

4. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the base station 2, namely, theSUL carrier configuration information of the at least one neighboringcell, which is a neighboring cell of any cell served by the base station2, the information indicating that the at least one neighboring cell ofthe at least one cell served by the base station 2 supports the SULcarrier. If each neighbor cell of any cell served by the base station 2does not support the SUL carrier, the information will not be included.

5. Identification information of at least one cell served by other basestation.

6. SUL carrier configuration information of the at least one cell servedby the other base station, the information indicating that the at leastone cell served by the other base station supports the SUL carrier. Ifeach cell served by the other base station does not support the SULcarrier, the information will not be included.

7. Identification information of at least one neighboring cell of the atleast one cell served by the other base station, namely, theidentification information of the at least one neighboring cell, whichis a neighboring cell of any cell served by the other base station.

8. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the other base station, namely,the SUL carrier configuration information of the at least oneneighboring cell, which is a neighboring cell of any cell served by theother base station, the information indicating that the at least oneneighbor cell of the at least one cell served by the other base stationsupports the SUL carrier. If each neighboring cell of any cell served bythe base station 1 does not support the SUL carrier, the informationwill not be included.

9. Indication information indicating that the at least one cell servedby the base station 2 supports the SUL carrier.

10. Indication information indicating that the at least one neighboringcell of the at least one cell served by the base station 2 supports theSUL carrier.

11. Indication information indicating that the at least one cell servedby the other base station supports the SUL carrier.

12. Indication information indicating that the at least one neighboringcell of the at least one cell served by the other base station supportsthe SUL carrier.

The information related to the other base station may be transmitted tothe base station 2 from the other base station.

In the above two steps, the messages 1 and 2 respectively may be anEN-DC X2 Setup request message and an EN-DC X2 Setup response message,an Xn Setup request message and an Xn Setup response message, an EN-DCConfiguration update message and an EN-DC Configuration updateacknowledge message, an Xn Configuration update message and an XnConfiguration update acknowledge message, or messages with other names.

Through the exchange by the above two steps, it helps each base stationto acquire whether the cell supported by the other base station supportsthe SUL carrier, and obtain related SUL carrier configurationinformation.

II. SUL carrier configuration information is exchanged between a centralunit and a distributed unit of a base station (triggered by thedistributed unit). Please refer to FIG. 10 (a).

Step 1: The distributed unit sends a message 3a (a configuration messagecarrying SUL carrier configuration information) to the central unit, themessage 3a including at least one of:

1. Identification information of at least one cell served by thedistributed unit of the base station.

2. SUL carrier configuration information of the at least one cell servedby the distributed unit of the base station, the information indicatingthat the at least one cell served by the distributed unit of the basestation supports the SUL carrier. If each cell served by the distributedunit of the base station does not support the SUL carrier, theinformation will not be included.

3. Identification information of at least one neighboring cell of the atleast one cell served by the distributed unit of the base station,namely, the identification information of the at least one neighboringcell, which is a neighboring cell of any cell served by the distributedunit of the base station.

4. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the distributed unit of the basestation, namely, the SUL carrier configuration information of the atleast one neighboring cell, which is a neighboring cell of any cellserved by the distributed unit of the base station, the informationindicating that the at least one neighboring cell of the at least onecell served by the distributed unit of the base station supports the SULcarrier. If each neighbor cell of any cell served by the distributedunit of the base station does not support the SUL carrier, theinformation will not be included.

5. Identification information of at least one cell served by other basestation.

6. SUL carrier configuration information of the at least one cell servedby the other base station, the information indicating that the at leastone cell served by the other base station supports the SUL carrier. Ifeach cell served by the other base station does not support the SULcarrier, the information will not be included.

7. Identification information of at least one neighboring cell of the atleast one cell served by the other base station, namely, theidentification information of the at least one neighboring cell, whichis a neighboring cell of any cell served by the other base station.

8. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the other base station, namely,the SUL carrier configuration information of the at least oneneighboring cell, which is a neighboring cell of any cell served by theother base station, the information indicating that the at least oneneighbor cell of the at least one cell served by the other base stationsupports the SUL carrier. If each neighboring cell of any cell served bythe base station 1 does not support the SUL carrier, the informationwill not be included.

9. Indication information indicating that the at least one cell servedby the distributed unit of the base station supports the SUL carrier.

10. Indication information indicating that the at least one neighboringcell of the at least one cell served by the distributed unit of the basestation supports the SUL carrier.

11. Indication information indicating that the at least one cell servedby the other base station supports the SUL carrier.

12. Indication information indicating that the at least one neighboringcell of the at least one cell served by the other base station supportsthe SUL carrier.

The information related to the other base station may be transmitted tothe distributed unit of the base station from the other base station, orfirstly transmitted to the central unit of the base station and then tothe distributed unit of the base station.

Step 2: The central unit feeds back a message 4a (an acknowledge messageof the SUL carrier configuration message) to the distributed unit,indicating that the central unit has received the message 3a sent by thedistributed unit. Further, optionally the message 4a may include atleast one of:

1. Identification information of at least one cell served by the centralunit.

2. SUL carrier configuration information of the at least one cell servedby the central unit, the information indicating that the at least onecell served by the central unit supports the SUL carrier. If each cellserved by the central unit does not support the SUL carrier, theinformation will not be included.

3. Identification information of at least one neighboring cell of the atleast one cell served by the central unit, namely, the identificationinformation of the at least one neighboring cell, which is a neighboringcell of any cell served by the central unit.

4. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the central unit, namely, theSUL carrier configuration information of the at least one neighboringcell, which is a neighboring cell of any cell served by the centralunit, the information indicating that the at least one neighboring cellof the at least one cell served by the central unit supports the SULcarrier. If each neighbor cell of any cell served by the central unitdoes not support the SUL carrier, the information will not be included.

5. Identification information of at least one cell served by other basestation.

6. SUL carrier configuration information of the at least one cell servedby the other base station, the information indicating that the at leastone cell served by the other base station supports the SUL carrier. Ifeach cell served by the other base station does not support the SULcarrier, the information will not be included.

7. Identification information of at least one neighboring cell of the atleast one cell served by the other base station, namely, theidentification information of the at least one neighboring cell, whichis a neighboring cell of any cell served by the other base station andacquired by the base station or the central unit of the base stationfrom the other base station.

8. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the other base station, namely,the SUL carrier configuration information of the at least oneneighboring cell, which is a neighboring cell of any cell served by theother base station and acquired by the base station or the central unitof the base station from the other base station, the informationindicating that the at least one neighbor cell of the at least one cellserved by the other base station supports the SUL carrier. If eachneighboring cell of any cell served by the other base station does notsupport the SUL carrier, the information will not be included.

9. Indication information indicating that the at least one cell servedby the central unit supports the SUL carrier.

10. Indication information indicating that the at least one neighboringcell of the at least one cell served by the central unit supports theSUL carrier.

11. Indication information indicating that the at least one cell servedby the other base station supports the SUL carrier.

12. Indication information indicating that the at least one neighboringcell of the at least one cell served by the other base station supportsthe SUL carrier.

The information related to the other base station may be transmitted tothe central unit of the base station from the other base station.

In the above two steps, the messages 3a and 4a respectively may be an F1Setup request message and an F1 Setup response message, a gNB-DUConfiguration Update message and a gNB-DU Configuration UpdateAcknowledge, or messages with other names.

Through the exchange by the above two steps, on one hand, it helps thecentral unit of each base station to acquire whether the cell served bythe distributed unit supports the SUL carrier and obtain related SULcarrier configuration, also to acquire whether the neighboring cell ofthe cell served by the distributed unit supports the SUL carrier andobtain related SUL carrier configuration; on the other hand, it helpsthe distributed unit of each base station to acquire whether the cellserved by the other base station supports the SUL carrier and obtainrelated SUL carrier configuration, also to acquire whether theneighboring cell of the cell served by the other base station supportsthe SUL carrier and obtain related SUL carrier configuration.

III. SUL carrier configuration information is exchanged between acentral unit and a distributed unit of a base station (triggered by thecentral unit). Please refer to FIG. 10 (b).

Step 1: The central unit sends a message 3b (a request message foracquiring an SUL carrier configuration) to the central unit, the message3b including at least one of:

1. Identification information of at least one cell served by the centralunit.

2. SUL carrier configuration information of the at least one cell servedby the central unit of the base station, the information indicating thatthe at least one cell served by the central unit of the base stationsupports the SUL carrier. If each cell served by the central unit of thebase station does not support the SUL carrier, the information will notbe included.

3. Identification information of at least one neighboring cell of the atleast one cell served by the central unit of the base station, namely,the identification information of the at least one neighboring cell,which is a neighboring cell of any cell served by the central unit ofthe base station.

4. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the central unit, namely, theSUL carrier configuration information of the at least one neighboringcell, which is a neighboring cell of any cell served by the centralunit, the information indicating that the at least one neighboring cellof the at least one cell served by the central unit supports the SULcarrier. If each neighbor cell of any cell served by the central unitdoes not support the SUL carrier, the information will not be included.

5. Identification information of at least one cell served by other basestation.

6. SUL carrier configuration information of the at least one cell servedby the other base station, the information indicating that the at leastone cell served by the other base station supports the SUL carrier. Ifeach cell served by the other base station does not support the SULcarrier, the information will not be included.

7. Identification information of at least one neighboring cell of the atleast one cell served by the other base station, namely, theidentification information of the at least one neighboring cell, whichis a neighboring cell of any cell served by the other base station andacquired by the base station or the central unit of the base stationfrom the other base station.

8. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the other base station, namely,the SUL carrier configuration information of the at least oneneighboring cell, which is a neighboring cell of any cell served by theother base station and acquired by the base station or the central unitof the base station from the other base station, the informationindicating that the at least one neighbor cell of the at least one cellserved by the other base station supports the SUL carrier. If eachneighboring cell of any cell served by the other base station does notsupport the SUL carrier, the information will not be included.

9. Indication information indicating that the at least one cell servedby the central unit supports the SUL carrier.

10. Indication information indicating that the at least one neighboringcell of the at least one cell served by the central unit supports theSUL carrier.

11. Indication information indicating that the at least one cell servedby the other base station supports the SUL carrier.

12. Indication information indicating that the at least one neighboringcell of the at least one cell served by the other base station supportsthe SUL carrier.

The information related to the other base station may be transmitted tothe central unit of the base station from the other base station.

Step 2: The distributed unit feeds back a message 4b (a configurationmessage carrying the SUL carrier configuration information) to thecentral unit, indicating that the distributed unit has received themessage 3b sent by the central unit. Further, optionally the message 4bmay include at least one of:

1. Identification information of at least one cell served by thedistributed unit of the base station.

2. SUL carrier configuration information of the at least one cell servedby the distributed unit of the base station, the information indicatingthat the at least one cell served by the distributed unit of the basestation supports the SUL carrier. If each cell served by the distributedunit of the base station does not support the SUL carrier, theinformation will not be included.

3. Identification information of at least one neighboring cell of the atleast one cell served by the distributed unit of the base station,namely, the identification information of the at least one neighboringcell, which is a neighboring cell of any cell served by the distributedunit of the base station.

4. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the distributed unit of the basestation, namely, the SUL carrier configuration information of the atleast one neighboring cell, which is a neighboring cell of any cellserved by the distributed unit of the base station, the informationindicating that the at least one neighboring cell of the at least onecell served by the distributed unit of the base station supports the SULcarrier. If each neighbor cell of any cell served by the distributedunit of the base station does not support the SUL carrier, theinformation will not be included.

5. Identification information of at least one cell served by other basestation.

6. SUL carrier configuration information of the at least one cell servedby the other base station, the information indicating that the at leastone cell served by the other base station supports the SUL carrier. Ifeach cell served by the other base station does not support the SULcarrier, the information will not be included.

7. Identification information of at least one neighboring cell of the atleast one cell served by the other base station, namely, theidentification information of the at least one neighboring cell, whichis a neighboring cell of any cell served by the other base station.

8. SUL carrier configuration information of the at least one neighboringcell of the at least one cell served by the other base station, namely,the SUL carrier configuration information of the at least oneneighboring cell, which is a neighboring cell of any cell served by theother base station, the information indicating that the at least oneneighbor cell of the at least one cell served by the other base stationsupports the SUL carrier. If each neighboring cell of any cell served bythe base station 1 does not support the SUL carrier, the informationwill not be included.

9. Indication information indicating that the at least one cell servedby the distributed unit of the base station supports the SUL carrier.

10. Indication information indicating that the at least one neighboringcell of the at least one cell served by the distributed unit of the basestation supports the SUL carrier.

11. Indication information indicating that the at least one cell servedby the other base station supports the SUL carrier.

12. Indication information indicating that the at least one neighboringcell of the at least one cell served by the other base station supportsthe SUL carrier.

The information related to the other base station may be transmitted tothe distributed unit of the base station from the other base station, orfirstly transmitted to the central unit of the base station and then tothe distributed unit of the base station.

In the above two steps, the messages 3b and 4b respectively may be agNB-CU Configuration Update message and a gNB-CU Configuration UpdateAcknowledge, or messages with other names.

Through the exchange by the above two steps, on one hand, it helps thedistributed unit of each base station to acquire whether the cell servedby the other base station supports the SUL carrier and obtain relatedSUL carrier configuration, also to acquire whether the neighboring cellof the cell served by the other base station supports the SUL carrierand obtain related SUL carrier configuration; on the other hand, ithelps the central unit of each base station to acquire whether the cellserved by the distributed unit supports the SUL carrier and obtainrelated SUL carrier configuration, also to acquire whether theneighboring cell of the cell served by the distributed unit supports theSUL carrier and obtain related SUL carrier configuration.

For one UE, the addition/modification/release of SUL carrier between acentral unit and a distributed unit of a base station may be implementedin one of the following manners.

Manner 1: the central unit of the base station determines theaddition/modification/release of the SUL carrier. Please refer to FIG.11.

Step 1: The central unit of the base station sends a message 5 (arequest message for acquiring an SUL carrier configuration) to thedistributed unit of the base station, the message 5 at least includesinformation related to the SUL carrier configuration of a cell andgenerated at the central unit side, and the information is related tothe SUL carrier configuration of at least one cell serving the user. Forone cell serving the user, the information includes at least one of:

1. Identification information of a cell which may be a Primary Cell(PCell), a Primary Secondary cell (PSCell), a Secondary cell (SCell), ora Secondary Cell Group (SCG) SCell.

2. Indication information related to an uplink carrier of the UE; theinformation may be explicit or implicit indication information, and maybe used to represent at least one of:

1) Indication information indicating to only configure a non-SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

2) Indication information indicating to only configure an SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

3) Indication information indicating to configure a non-SUL carrier andan SUL carrier for the UE, or indication information indicating toconfigure an SUL carrier for the UE, or indication informationindicating to activate the SUL carrier, or indication informationindicating to add an SUL carrier for the UE. The indication informationindicates that if the “information related to an uplink carrier of theUE” is not included, it is defaulted to only configure a non-SUL carrierfor the UE, and if the “information related to an uplink carrier of theUE” is included, it is indicated to configure a non-SUL carrier and anSUL carrier for the UE. In another embodiment, the indicationinformation may also be represented in a manner not including the“information related to an uplink carrier of the UE”.

3. Indication information related to a modification of the uplinkcarrier configuration of the UE; the information may be explicit orimplicit indication information, and may be used to represent at leastone of:

1) indication information indicating to modify an SUL carrierconfiguration of the UE;

2) indication information indicating to modify a non-SUL carrierconfiguration of the UE; and

3) indication information indicating to modify an SUL carrierconfiguration and a non-SUL carrier configuration of the UE.

4. Indication information indicating to configure random access-relatedinformation (cell-specific or UE-specific) on the SUL carrier for theUE.

5. Indication information indicating to modify random access-relatedinformation (cell-specific and/or UE-specific) on the SUL carrier forthe UE.

The cell serving the user in the above information may be a cell newlyadded for the user in one embodiment, or a cell currently serving theuser in another embodiment.

II. Information related to measurement results of a cell, which mayinclude at least one of:

1. identification information of the cell;

2. signal strength information (RSRP), or signal quality information(RSRQ), or Signal to Interference and Noise Ratio (SINR) information,etc. of the cell; and

3. measurement information related to a Synchronization Signal block(SSB, including PSS, SSS and PBCH) of the cell; the measurementinformation may be acquired by measuring signals (e.g., PSS, SSS, PBCH,DM-RS and CSI-RS) in the signal block, and may include at least one of:

1) identification information of at least one synchronization signalblock; further, the identification information may be used to indicatelocation information of the synchronization signal block;

2) measurement results of the at least one synchronization signal block,such as RSRP, RSRQ, SINR, etc.;

3) identification information of at least one suitable synchronizationsignal block selected by the UE; further, the identification informationmay be used to indicate location information of the synchronizationsignal block; and

4) measurement results of at least one suitable synchronization signalblock selected by the UE, such as RSRP, RSRQ, SINR, etc.

In addition, the information related to the measurement results of thecell may also include the measurement results of other cells not servingthe user.

Step 2: The distributed unit of the base station sends a message 6 (aconfiguration message carrying the SUL carrier configurationinformation) to the central unit of the base station. The message 6 is aresponse message to the message 5 in step 1 and at least includesinformation related to the SUL carrier configuration of the cellgenerated at the distributed unit side. The information is related tothe SUL carrier configuration of at least one cell serving the user. Fora cell serving the user, the information includes at least one of:

1. identification information of the cell;

2. indication information related to an uplink carrier of the UE; theinformation may be explicit or implicit indication information, and maybe used to represent at least one of:

1) Indication information indicating to only configure a non-SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

2) Indication information indicating to only configure an SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

3) Indication information indicating to configure a non-SUL carrier andan SUL carrier for the UE, or indication information indicating toconfigure an SUL carrier for the UE, or indication informationindicating to activate the SUL carrier, or indication informationindicating to add an SUL carrier for the UE. The indication informationindicates that if the “information related to an uplink carrier of theUE” is not included, it is defaulted to only configure a non-SUL carrierfor the UE, and if the “information related to an uplink carrier of theUE” is included, it is indicated to configure a non-SUL carrier and anSUL carrier for the UE. In another embodiment, the indicationinformation may also be represented in a manner not including the“information related to an uplink carrier of the UE”.

3. Indication information related to a modification of the uplinkcarrier configuration of the UE; the information may be explicit orimplicit indication information, and may be used to represent at leastone of:

1) indication information indicating to modify an SUL carrierconfiguration of the UE;

2) indication information indicating to modify a non-SUL carrierconfiguration of the UE; and

3) indication information indicating to modify an SUL carrierconfiguration and a non-SUL carrier configuration of the UE.

4. Indication information indicating to configure random access-relatedinformation (cell-specific and/or UE-specific) on the SUL carrier forthe UE.

5. Indication information indicating to modify random access-relatedinformation (cell-specific and/or UE-specific) on the SUL carrier forthe UE.

6. SUL carrier configuration information of the cell.

7. Non-SUL carrier configuration information of the cell. For theconfiguration parameters that might be included in the configurationinformation, please refer to the configuration parameters included inthe SUL carrier configuration information.

The cell serving the user in the above information may be a cell newlyadded for the user in one embodiment, or a cell currently serving theuser in another embodiment. The information related to the SUL carrierconfiguration may be generated by the distributed unit according to themessage of step 1 or determined by the distributed unit itself.

Before step 1, optionally there may be step 0. That is, the central unitof the base station receives information related to the measurementresults of the cell and reported by the UE. The information istransmitted by the UE to the distributed unit and then by thedistributed unit to the central unit, or received by the central unit ofthe base station from other base station. The information related to themeasurement results of the cell includes at least one of (the cellincluded in the information may not be the cell serving the user):

1. identification information of the cell;

2. signal strength information (RSRP), or signal quality information(RSRQ), or Signal to Interference and Noise Ratio (SINR) information,etc. of the cell; and

3. measurement information related to a Synchronization Signal block(SSB, including PSS, SSS and PBCH) of the cell; the measurementinformation may be acquired by measuring signals (e.g., PSS, SSS, PBCH,DM-RS and CSI-RS) in the signal block, and may include at least one of:

1) identification information of at least one synchronization signalblock; further, the identification information may be used to indicatelocation information of the synchronization signal block;

2) measurement results of the at least one synchronization signal block,such as RSRP, RSRQ, SINR, etc.;

3) identification information of at least one suitable synchronizationsignal block selected by the UE; further, the identification informationmay be used to indicate location information of the synchronizationsignal block; and

4) measurement results of at least one suitable synchronization signalblock selected by the UE, such as RSRP, RSRQ, SINR, etc.

After step 2, optionally there may be step 3. That is, the configurationinformation received in step 2 may be transmitted by the central unit ofthe base station to the UE through the distributed unit or other basestation.

The above steps 1 and 2 may be applied to the UE context setup procedurebetween the central unit and the distributed unit, or the UE contextmodification procedure initiated by the central unit, or any otherprocedure. The messages 5 and 6 respectively may be a UE Context SetupRequest message and a UE Context Setup Response message, a UE ContextModification Request message and an UE Modification Response message, ormessages with other names.

Through the exchange by the above two steps, it helps the distributedunit of the base station to generate a non-SUL carrier configurationand/or an SUL carrier configuration for the UE and finally transmit tothe UE.

The manner may be extensionally applied to the case of two base stations(base stations 1 and 2) (the interface between the two base stations maybe X2/Xn, or any other interface) to achieve anaddition/modification/release of the SUL carrier of the UE initiated bythe base station 1. The specific method is similar to the abovedescription, i.e., the central unit in steps 1 and 2 is changed to bebase station 1, and the distributed unit is changed to be base station2. For step 0, the base station 1 may acquire cell measurementinformation (refer to the foregoing description) reported by the UE. Themeasurement information may be reported by the UE or transmitted byother base station. For step 3, the configuration information of the UEmay be transmitted to the UE through the base station 1 or the basestation 2. The exchange between the above two base stations may beapplied to a handover process, then the messages 5 and 6 in steps 1 and2 are a Handover Request message and a Handover Request Acknowledgemessage, respectively; the above exchange may also be applied to adual-connection establishment process, then the messages 5 and 6 insteps 1 and 2 are an S-Node Addition Request and an S-Node AdditionRequest Acknowledge, respectively, or an SgNB Addition Request messageand an SgNB Addition Request Acknowledge message, respectively; theabove exchange may further be applied to a dual-connection modificationprocess, then the messages 5 and 6 in steps 1 and 2 are an S-NodeModification Request and an S-Node Modification Request Acknowledge,respectively, or an SgNB Modification Request message and an SgNBModification Request Acknowledge message, respectively. In addition, theabove exchange may also be applied to other process and other messagesmay be used.

In addition, for the initial access by the UE, if the UE selects aprocess of performing a random access on the SUL carrier, thedistributed unit may transmit to the central unit indication informationindicating that the UE select to perform a random access on the SULcarrier. Further, the indication information may indicate that thedistributed unit has provided the SUL carrier configuration informationto the central unit. Optionally, after receiving the indicationinformation, the central unit may trigger the distributed unit toprovide the SUL carrier configuration information in the manner of steps1 and 2. Please refer to FIG. 12.

Step 0a: The distributed unit acquires that the UE performs a randomaccess on the SUL carrier. The distributed unit may determine whether toperform a random access on the SUL carrier according to the carrierreceiving the random access signal.

Step 0b: The distributed unit transmits to the central unit indicationinformation indicating that a random access is performed on the SULcarrier. The indication information may be transmitted in an Initial ULRRC message or any other message. Optionally, the message may furthercarry the SUL carrier configuration information.

Optionally, the SUL carrier may be further configured according to theabove steps 1 and 2.

Step 3: The central unit of the base station transmits the SUL carrierconfiguration information to the UE. The SUL carrier configurationinformation may be transmitted to the UE through the distributed unit orother base station.

Manner 2: The distributed unit of the base station determines theaddition/modification/release of the SUL carrier (the central unitprovides auxiliary information). Please refer to FIG. 13.

Step 1: The central unit of the base station sends a message 7 (arequest message for acquiring an SUL carrier configuration) to thedistributed unit of the base station, the message 7 at least includinginformation related to measurement results of a cell (the cell includedin the information may not be the cell serving the user), andspecifically including at least one of:

1. identification information of the cell;

2. signal strength information (RSRP), or signal quality information(RSRQ), or Signal to Interference and Noise Ratio (SINR) information,etc. of the cell;

3. measurement information related to a Synchronization Signal block(SSB, including PSS, SSS and PBCH) of the cell; the measurementinformation may be acquired by measuring signals (e.g., PSS, SSS, PBCH,DM-RS and CSI-RS) in the signal block, and may include at least one of:

1) identification information of at least one synchronization signalblock; further, the identification information may be used to indicatelocation information of the synchronization signal block;

2) measurement results of the at least one synchronization signal block,such as RSRP, RSRQ, SINR, etc.;

3) identification information of at least one suitable synchronizationsignal block selected by the UE; further, the identification informationmay be used to indicate location information of the synchronizationsignal block; and

4) measurement results of at least one suitable synchronization signalblock selected by the UE, such as RSRP, RSRQ, SINR, etc.

Step 2: The distributed unit of the base station sends a message 8 (aconfiguration message carrying the SUL carrier configurationinformation) to the central unit of the base station. The message 8 is aresponse message to the message 7 in step 1 and at least includesinformation related to the SUL carrier configuration of the cellgenerated at the distributed unit side. The information is related tothe SUL carrier configuration of at least one cell serving the user. Fora cell serving the user, the information includes at least one of:

1. identification information of the cell;

2. indication information related to an uplink carrier of the UE; theinformation may be explicit or implicit indication information, and maybe used to represent at least one of:

1) Indication information indicating to only configure a non-SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

2) Indication information indicating to only configure an SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

3) Indication information indicating to configure a non-SUL carrier andan SUL carrier for the UE, or indication information indicating toconfigure an SUL carrier for the UE, or indication informationindicating to activate the SUL carrier, or indication informationindicating to add an SUL carrier for the UE. The indication informationindicates that if the “information related to an uplink carrier of theUE” is not included, it is defaulted to only configure a non-SUL carrierfor the UE, and if the “information related to an uplink carrier of theUE” is included, it is indicated to configure a non-SUL carrier and anSUL carrier for the UE. In another embodiment, the indicationinformation may also be represented in a manner not including the“information related to an uplink carrier of the UE”.

3. Indication information related to a modification of the uplinkcarrier configuration of the UE; the information may be explicit orimplicit indication information, and may be used to represent at leastone of:

1) indication information indicating to modify an SUL carrierconfiguration of the UE;

2) indication information indicating to modify a non-SUL carrierconfiguration of the UE; and

3) indication information indicating to modify an SUL carrierconfiguration and a non-SUL carrier configuration of the UE.

4. Indication information indicating to configure random access-relatedinformation (cell-specific and/or UE-specific) on the SUL carrier forthe UE.

5. Indication information indicating to modify random access-relatedinformation (cell-specific and/or UE-specific) on the SUL carrier forthe UE.

6. SUL carrier configuration information of the cell.

7. Non-SUL carrier configuration information of the cell. For theconfiguration parameters that might be included in the configurationinformation, please refer to the configuration parameters included inthe SUL carrier configuration information.

The cell serving the user in the above information may be a cell newlyadded for the user in one embodiment, or a cell currently serving theuser in another embodiment. The information related to the SUL carrierconfiguration may be generated by the distributed unit according to themessage of step 1 or determined by the distributed unit itself.

Before step 1, optionally there may be step 0. That is, the central unitof the base station receives information related to the measurementresults of the cell and reported by the UE. The information istransmitted by the UE to the distributed unit and then by thedistributed unit to the central unit, or received by the central unit ofthe base station from other base station. The information related to themeasurement results of the cell includes at least one of (the cellincluded in the information may not be the cell serving the user):

1. identification information of the cell;

2. signal strength information (RSRP), or signal quality information(RSRQ), or Signal to Interference and Noise Ratio (SINR) information,etc. of the cell; and

3. measurement information related to a Synchronization Signal block(SSB, including PSS, SSS and PBCH) of the cell; the measurementinformation may be acquired by measuring signals (e.g., PSS, SSS, PBCH,DM-RS and CSI-RS) in the signal block, and may include at least one of:

1) identification information of at least one synchronization signalblock; further, the identification information may be used to indicatelocation information of the synchronization signal block;

2) measurement results of the at least one synchronization signal block,such as RSRP, RSRQ, SINR, etc.;

3) identification information of at least one suitable synchronizationsignal block selected by the UE; further, the identification informationmay be used to indicate location information of the synchronizationsignal block; and

4) measurement results of at least one suitable synchronization signalblock selected by the UE, such as RSRP, RSRQ, SINR, etc.

After step 2, optionally there may be step 3. That is, the configurationinformation received in step 2 may be transmitted by the central unit ofthe base station to the UE through the distributed unit or other basestation.

The above steps 1 and 2 may be applied to the UE context setup procedurebetween the central unit and the distributed unit, or the UE contextmodification procedure initiated by the central unit, or any otherprocedure. The messages 7 and 8 respectively may be a UE Context SetupRequest message and a UE Context Setup response message, a UE ContextModification Request message and a UE Context Modification Responsemessage, or messages with other names.

Through the exchange by the above two steps, it helps the distributedunit of the base station to generate a non-SUL carrier configurationand/or an SUL carrier configuration for the UE and finally transmits thesame to the UE.

The manner may be extensionally applied to the case of two base stations(base stations 1 and 2) (the interface between the two base stations maybe X2/Xn, or any other interface) to achieve anaddition/modification/release of the SUL carrier determined by the basestation 2. The specific method is similar to the above description,i.e., the central unit in steps 1 and 2 is changed to be base station 1,and the distributed unit is changed to be base station 2. For step 0,the base station 1 may acquire cell measurement information (refer tothe foregoing description) reported by the UE. The measurementinformation may be reported by the UE or transmitted by other basestation. For step 3, the configuration information of the UE may betransmitted to the UE through the base station 1 or the base station 2.The exchange between the above two base stations may be applied to ahandover process, then the messages 7 and 8 in steps 1 and 2 are aHandover Request message and a Handover Request Acknowledge message,respectively; the above exchange may also be applied to adual-connection establishment process, then the messages 7 and 8 insteps 1 and 2 are an S-Node Addition Request and an S-Node AdditionRequest Acknowledge, respectively, or an SgNB Addition Request messageand an SgNB Addition Request Acknowledge message, respectively; theabove exchange may further be applied to a dual-connection modificationprocess, then the messages 7 and 8 in steps 1 and 2 are an S-NodeModification Request and an S-Node Modification Request Acknowledge,respectively, or an SgNB Modification Request message and an SgNBModification Request Acknowledge message, respectively. In addition, theabove exchange may also be applied to other process and other messagesmay be used.

Manner 3: the distributed unit of the base station determines theaddition/modification/release of the SUL carrier. Please refer to FIG.14.

Step 1: The distributed unit of the base station sends a message 9 (aconfiguration message carrying the SUL carrier configurationinformation) to the central unit of the base station. The message 9 atleast includes information related to the SUL carrier configuration ofthe cell generated at the distributed unit side. The information isrelated to the SUL carrier configuration of at least one cell servingthe user. For a cell serving the user, the information includes at leastone of:

1. identification information of the cell;

2. indication information related to an uplink carrier of the UE; theinformation may be explicit or implicit indication information, and maybe used to represent at least one of:

1) Indication information indicating to only configure a non-SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

2) Indication information indicating to only configure an SUL carrierfor the UE. In another embodiment, the indication information may alsobe represented in a manner not including the “information related to anuplink carrier of the UE”.

3) Indication information indicating to configure a non-SUL carrier andan SUL carrier for the UE, or indication information indicating toconfigure an SUL carrier for the UE, or indication informationindicating to activate the SUL carrier, or indication informationindicating to add an SUL carrier for the UE. The indication informationindicates that if the “information related to an uplink carrier of theUE” is not included, it is defaulted to only configure a non-SUL carrierfor the UE, and if the “information related to an uplink carrier of theUE” is included, it is indicated to configure a non-SUL carrier and anSUL carrier for the UE. In another embodiment, the indicationinformation may also be represented in a manner not including the“information related to an uplink carrier of the UE”.

3. Indication information related to a modification of the uplinkcarrier configuration of the UE; the information may be explicit orimplicit indication information, and may be used to represent at leastone of:

1) indication information indicating to modify an SUL carrierconfiguration of the UE;

2) indication information indicating to modify a non-SUL carrierconfiguration of the UE; and

3) indication information indicating to modify an SUL carrierconfiguration and a non-SUL carrier configuration of the UE.

4. Indication information indicating to configure random access-relatedinformation (cell-specific and/or UE-specific) on the SUL carrier forthe UE.

5. Indication information indicating to modify random access-relatedinformation (cell-specific and/or UE-specific) on the SUL carrier forthe UE.

6. SUL carrier configuration information of the cell.

7. Non-SUL carrier configuration information of the cell. For theconfiguration parameters that might be included in the configurationinformation, please refer to the configuration parameters included inthe SUL carrier configuration information.

The cell serving the user in the above information may be a cell newlyadded for the user in one embodiment, or a cell currently serving theuser in another embodiment. The information related to the SUL carrierconfiguration may be generated by the distributed unit according to themessage of step 1 or determined by the distributed unit itself.

Step 2: The central unit of the base station sends a message 10 (anacknowledge message of the SUL carrier configuration) to the distributedunit of the base station, the message 10 acknowledging the correctreception of the message 9.

Before step 1, optionally there may be step 0. That is, the distributedunit of the base station acquires information related to the measurementresults of the cell from the central unit. The information may betransmitted by the UE to the central unit through the distributed unit,or received by the central unit of the base station from other basestation. The information includes at least one of (the cell included inthe information may not be the cell serving the user):

1. identification information of the cell;

2. signal strength information (RSRP), or signal quality information(RSRQ), or Signal to Interference and Noise Ratio (SINR) information,etc. of the cell; and

3. measurement information related to a Synchronization Signal block(SSB, including PSS, SSS and PBCH) of the cell; the measurementinformation may be acquired by measuring signals (e.g., PSS, SSS, PBCH,DM-RS and CSI-RS) in the signal block, and may include at least one of:

1) identification information of at least one synchronization signalblock; further, the identification information may be used to indicatelocation information of the synchronization signal block;

2) measurement results of the at least one synchronization signal block,such as RSRP, RSRQ, SINR, etc.;

3) identification information of at least one suitable synchronizationsignal block selected by the UE; further, the identification informationmay be used to indicate location information of the synchronizationsignal block;

4) measurement results of at least one suitable synchronization signalblock selected by the UE, such as RSRP, RSRQ, SINR, etc.

After step 2, optionally there may be step 3. That is, the configurationinformation received in step 1 may be transmitted by the central unit ofthe base station to the UE through the distributed unit or other basestation.

The above steps 1 and 2 may be applied to the UE context modificationprocedure initiated by the distributed unit, or any other procedure. Themessages 9 and 10 respectively may be a UE Context Modification Requiredmessage and a UE Context Modification Confirm message, or messages withother names.

Through the exchange by the above two steps, it helps the distributedunit of the base station to generate a non-SUL carrier configurationand/or an SUL carrier configuration for the UE and finally transmits thesame to the UE.

The manner may be extensionally applied to the case of two base stations(base stations 1 and 2) (the interface between the two base stations maybe X2/Xn, or any other interface) to achieve anaddition/modification/release of the SUL carrier initiated by the basestation 2. The specific method is similar to the above description,i.e., the central unit in steps 1 and 2 is changed to be base station 1,and the distributed unit is changed to be base station 2. For step 0,the base station 2 may acquire cell measurement information (refer tothe foregoing description) reported by the UE. For step 3, theconfiguration information of the UE may be transmitted to the UE throughthe base station 1 or the base station 2. The exchange between the abovetwo base stations may be applied to a dual-connection modificationprocess, then the messages 9 and 10 in steps 1 and 2 are an S-NodeModification Required message and an S-Node Modification Confirmmessage, respectively, or an SgNB Modification Required message and anSgNB Modification Confirm message, respectively. In addition, the aboveexchange may also be applied to other process and other messages may beused.

In a case where a failure occurs after UE is connected to a network, theUE cannot be communicated with a base station or a distributed unit inthe base station.

I. If a cell of the UE served by the base station or the distributedunit of the base station is a PCell (or MCG PCell) and further mayinclude an SCell (or MCG SCell), as shown in FIG. 15, the cause of thefailure may be one of the following “cause information 1” (please referto related indication information in RLF-Report in TS36.331 or TS38.331for an implementation):

1. The timer expires. For example, T310 expires and T312 expires, andplease refer to t310-Expiry and t312-Expiry in TS36.331 or TS38.331 foran implementation.

2. The random access problem. In one embodiment, the random accessproblem indicates that a random access failure occurs in the PCell (orMCG PCell), or in the SCell (or MCG SCell) of the base station, andplease refer to randomAccessProblem in TS36.331 or TS38.331 for animplementation.

3. The number of retransmissions of the RLC layer of the UE exceeds themaximum number of retransmissions thereof, and please refer torlc-MaxNumRetx in TS36.331 or TS38.331 for an implementation; or it maybe indicated that an RLC is failed.

4. The cause of connection failure, such as a radio link failure or ahandover failure, and please refer to connectionFailureType in TS36.331or TS38.331 for an implementation. II. If a cell of the UE served by thebase station or the distributed unit of the base station is a PSCell (orSCG PSCell) and further may include an SCG SCell, as shown in FIG. 16,the cause of the failure may be one of the following “cause information2” (please refer to related indication information inSCGFailurelnformation or FailureReportSCG-ToOtherRAT in TS36.331 orTS38.331 for an implementation):

1. The timer expires. For example, T313 expires, and please refer tot313-Expiry in TS36.331 or TS38.331 for an implementation.

2. The random access problem. In one embodiment, the random accessproblem indicates that a random access failure occurs in the PSCell (orSCG PSCell), or in the SCG SCell, and please refer torandomAccessProblem in TS36.331 or TS38.331 for an implementation.

3. The number of retransmissions of the RLC layer of the UE exceeds themaximum number of retransmissions thereof. This event occurs at a basestation where the SCG is located, and please refer to rlc-MaxNumRetx inTS36.331 or TS38.331 for an implementation; or it may be indicated thatan RLC is failed.

4. The SCG change is failed. This event indicates that the UE fails tochange the base station or the distributed unit thereof serving the SCG,and please refer to scg-ChangeFailure in TS36.331 or TS38.331 for animplementation.

5. The maximum uplink transmission time difference is exceeded, andplease refer to maxUL-TimingDiff in TS36.331 or TS38.331 for animplementation.

6. The SCG reconfiguration is failed. This event indicates that thereconfiguration of the SCG of the UE is failed, and please refer toscg-reconfigFailure in TS36.331 or TS38.331 for an implementation.

7. The integrity protection of signaling sent in the SCG is failed, andplease refer to srb3-IntegrityFailure in TS36.331 or TS38.331 for animplementation.

After the SUL carrier is introduced, the above failures of the UE mayoccur when the UE uses the SUL carrier, or the non-SUL carrier, or bothof them to communicate with the network. However, in the prior art, whenthe UE reports the causes of failures, it is not indicated whether thosefailures occur when the SUL carrier, or the non-SUL carrier, or both ofthem are used. Thus, the present disclosure provides the followingmechanisms of reporting the causes of the failures.

Mechanism I: The UE reports to the network side entities. Please referto FIG. 17.

Step 1: The UE sends to the network side entities a failure reportmessage containing information related to a link failure, and at leastincluding one of:

I. Cause information of the UE failure, including at least one of thecause information 1 and/or the cause information 2.

II. Information related to the use of the SUL carrier by the UE, whichmay be at least one of:

1. indication information indicating that the UE uses the non-SULcarrier; in one embodiment, the indication information indicates thatthe UE uses the non-SUL carrier; in another embodiment, the indicationinformation indicates that in the failure judging process, the UE usesthe non-SUL carrier; in still another embodiment, the indicationinformation indicates that the UE failure is caused by the use of thenon-SUL carrier; in yet another embodiment, the indication informationindicates that at a moment when the UE judges the link to be failed, theUE uses the non-SUL carrier;

2. indication information indicating that the UE uses the SUL carrier;in one embodiment, the indication information indicates that the UE usesthe SUL carrier; in another embodiment, the indication informationindicates that in the failure judging process, the UE uses the SULcarrier;

in still another embodiment, the indication information indicates thatthe UE failure is caused by the use of the SUL carrier; in yet anotherembodiment, the indication information indicates that at a moment whenthe UE judges the link to be failed, the UE uses the SUL carrier; and

3. indication information indicating that the UE uses the SUL carrierand the non-SUL carrier; in one embodiment, the indication informationindicates that the UE uses the SUL carrier and the non-SUL carrier; inanother embodiment, the indication information indicates that in thefailure judging process, the UE uses the SUL carrier and the non-SULcarrier; in still another embodiment, the indication informationindicates that the UE failure is caused by the use of the SUL carrierand the non-SUL carrier; in yet another embodiment, the indicationinformation indicates that at a moment when the UE judges the link to befailed, the UE uses the SUL carrier and the non-SUL carrier.

For example, if the information reported by the UE includes: 1) therandom access problem, and 2) indication information indicating that theUE uses the SUL carrier, it means that the UE fails because a failureoccurs during the random access on the SUL carrier. For another example,if the information reported by the UE includes: 1) the problem that thenumber of retransmissions of the RLC layer of the UE exceeds the maximumnumber of retransmissions thereof, and 2) indication informationindicating that the UE uses the SUL carrier, it means that the UE failsbecause when the SUL carrier is used for communications, the number ofretransmissions of the RLC layer exceeds the maximum number ofretransmissions thereof.

In addition, the “cause information of the UE failure” and the“information related to the use of the SUL carrier” may also berepresented just with one piece of indication information. In this step,there are two possibilities for the UE to report to the network:

Possibility 1: after the failure, the UE is reconnected to a cell (cell2) which may be different from the serving cell (cell 1) when the UEfails. In one embodiment, the cells 1 and 2 are located in differentbase stations, or in different distributed units of the same basestation, or in the same base station. The UE reports the information tothe base station where the cell 2 is located, or to the distributed unitof the base station where the cell 2 is located and then the distributedunit reports the information to the central unit of the base station.

Possibility 2: after the failure, the UE still remains a connection withanother base station or another distributed unit of the same basestation (before the failure, the UE is communicated with two basestations or two distributed units of one base station), and the UEreports the information to the base station remained in connection, orto the distributed unit of the base station remained in connection andthen the distributed unit reports the information to the central unit ofthe base station.

Optionally, there may be step 0 before step 1: the base station sends afailure report request message to the UE to request the UE to reportfailure cause information; or the central unit of the base station sendsa failure report request message to the distributed unit, and then thedistributed unit sends the request message to the UE.

Optionally, there may be step 2 after step 1: the base station or thecentral unit thereof receiving the “information related to a linkfailure” sends a failure notification message including a part or wholeof the “information related to a link failure” to the base station (orthe central unit thereof) where the UE is failed. This step may occurwhen the base station or the central unit thereof receiving the“information related to a link failure” is different from the basestation where the UE is failed.

The effect of this mechanism is to help the base station to determinethe uplink carrier used by the UE in the event of a failure, and furtherhelp the base station to optimize the configuration parameters of theuser served by the base station and to reduce the probability offailure.

Mechanism II: the distributed unit reports to the central unit. Pleaserefer to FIG. 18.

Step 1: The distributed unit sends to the central unit a failure reportmessage that is generated by the distributed unit based on a failureoccurring in a communication with the UE and contains informationrelated to a link failure, at least including one of:

I. Cause information of the UE failure, including at least one of thecause information 1 and/or the cause information 2.

II. Information related to the use of the SUL carrier by the UE, whichmay be at least one of:

1. indication information indicating that the UE uses the non-SULcarrier; in one embodiment, the indication information indicates thatthe UE uses the non-SUL carrier; in another embodiment, the indicationinformation indicates that in the failure judging process, the UE usesthe non-SUL carrier; in still another embodiment, the indicationinformation indicates that the UE failure is caused by the use of thenon-SUL carrier; in yet another embodiment, the indication informationindicates that at a moment when the UE judges the link to be failed, theUE uses the non-SUL carrier;

2. indication information indicating that the UE uses the SUL carrier;in one embodiment, the indication information indicates that the UE usesthe SUL carrier; in another embodiment, the indication informationindicates that in the failure judging process, the UE uses the SULcarrier;

in still another embodiment, the indication information indicates thatthe UE failure is caused by the use of the SUL carrier; in yet anotherembodiment, the indication information indicates that at a moment whenthe UE judges the link to be failed, the UE uses the SUL carrier; and

3. indication information indicating that the UE uses the SUL carrierand the non-SUL carrier; in one embodiment, the indication informationindicates that the UE uses the SUL carrier and the non-SUL carrier; inanother embodiment, the indication information indicates that in thefailure judging process, the UE uses the SUL carrier and the non-SULcarrier; in still another embodiment, the indication informationindicates that the UE failure is caused by the use of the SUL carrierand the non-SUL carrier; in yet another embodiment, the indicationinformation indicates that at a moment when the UE judges the link to befailed, the UE uses the SUL carrier and the non-SUL carrier.

For example, if the information reported includes: 1) the random accessproblem, and 2) indication information indicating that the UE uses theSUL carrier, it means that the UE fails because a failure occurs duringthe random access on the SUL carrier. For another example, if theinformation reported includes: 1) the problem that the number ofretransmissions of the RLC layer of the UE exceeds the maximum number ofretransmissions thereof, and 2) indication information indicating thatthe UE uses the SUL carrier, it means that the UE fails because when theSUL carrier is used for communications, the number of retransmissions ofthe RLC layer exceeds the maximum number of retransmissions thereof.

In addition, the “cause information of the UE failure” and the“information related to the use of the SUL carrier” may also berepresented just with one piece of indication information. Optionally,there may be step 0 before step 1: the central unit sends a failurereport request message to the distributed unit to request thedistributed unit to report the information related to the link failure.

Optionally, there may be step 2 after step 1: the central unit sends tothe distributed unit a failure report acknowledge message thatacknowledges reception of the message sent by the distributed unit instep 1; or the central unit of the base station sends a failurenotification message including a part or whole of the “informationrelated to a link failure” to the base station (or the central unitthereof) where the UE is failed.

The effect of this mechanism is to help the central unit to determinethe uplink carrier used by the UE in the event of a failure, and furtherhelp the base station to optimize the configuration parameters thereof,which may be the configuration parameters required by the served user orthose of the serving cell, and to reduce the probability of failure.

Please refer to FIG. 19, a network-side device for transferringsupplementary uplink carrier configuration information in the presentdisclosure includes:

an SUL carrier configuration information acquiring module configured toacquire SUL carrier configuration information;an SUL carrier configuration information transmitting module configuredto transmit a message containing the SUL carrier configurationinformation to a network-side entity, so that the network-side entityacquires a resource configuration status of other network-side entity;further, the network-side entity may configure a UE with an SUL carrier.

The working processes of the SUL carrier configuration informationacquiring module and the SUL carrier configuration informationtransmitting module are corresponding to steps 101 and 102 in the methodfor transferring the supplementary uplink carrier configurationinformation in the present disclosure, respectively, which are omittedherein.

From the detailed description of the present disclosure, it may be seenthat the present disclosure at least has the following advantageoustechnical effects as compared with the prior art: Firstly, bytransferring and exchanging the SUL carrier configuration informationbetween the network-side entities, a base station (or a central unit ofa base station) acquires an SUL carrier configuration of other basestation (or a distributed unit of a base station), so that anetwork-side entity may determine whether to select a cell containingthe SUL carrier for the UE, and acquire the resource status of othernetwork-side entity, thereby fully utilizing the SUL carrier to expandthe system uplink coverage.

Secondly, by adding/modifying/releasing an SUL carrier for the UE at thenetwork-side entity, the network side determines, according to thechannel state of the UE, to trigger the network entity to configure theUE with a SUL carrier-containing cell and an SUL carrier. Meanwhile,when the UE hands over or a dual-connection is configured for the UE, itfurther helps to select a suitable cell and configure an SUL carrier forthe user.

Thirdly, the configuration parameters of the network-side entity (whichmay be configuration parameters required by the served user, orconfiguration parameters of the serving cell) are optimized according tothe radio link failure information of the UE on the SUL carrier, and SULcarrier configurations at the network side and the UE side arecorrected, which reduces the probability of UE communication failure andincreases the reliability of the system FIG. 20 schematically shows asystem architecture diagram of an example of a next generation mobilecommunication system, such as a fifth generation (5G) mobilecommunication system. As shown, the system mainly includes a userequipment (UE) 11, a next generation radio access network (NG-RAN) 12,an Access and Mobility Management Function (AMF) 13, User Plane Function(UPF) 14, Session Management Function Entity (SMF) 15, Data Network (DN)16. The Access and Mobility Management Function (AMF) 13, the User PlaneFunction (UPF) 14 and the Session Management Function Entity (SMF) 15may be considered as being located in a next generation core network(such as 5GC). It should be understood that the devices in the figuresare for purposes of exemplification only and that the system may includenumerous UEs, one or more radio access networks, one or more datanetworks, and other devices, among others.

The user equipment (UE) 11 is a terminal device for receiving data. Asused herein, the terms “user equipment” and “UE” may, in some cases,refer to a mobile device, such as a mobile phone, a personal digitalassistant, a hand-held or laptop computer, and similar devices withcommunication capabilities. In other cases, the terms “user equipment”and “UE” may also refer to devices that have similar capabilities butare not portable, such as a desktop computer, a set-top box, or anetwork device.

The next generation radio access network (NG-RAN) 12 is a radio accessnetwork. The NG-RAN 12 includes a base station that provides the UE withaccess to a wireless network interface. The base station may be anext-generation base station (gNB) or an eNB connected to anext-generation core network (such as 5GC).

The Access and Mobility Management Function (AMF) 13 is responsible formanaging the UEs mobile context, security information, etc.

The User Plane Function Entity (UPF) 14 mainly provides user planefunctions.

The Session Management Function Entity (SMF) 15 is responsible forsession management.

The Data Network (DN) 16 contains services such as carrier services,Internet access and third-party services. NG1 is the interface betweenthe UE and the AMF.

NG-C is the control plane interface between the AMF and the NG-RAN. NG-Uis the user plane interface between the NG-RAN and the UPF. NG6 is theinterface between the UPF and the DN. NG4 is the interface between theUPF and the SMF.

FIG. 21 schematically shows a structural diagram of an example of a basestation (such as a gNB) of an exemplary next generation mobilecommunication system (such as a 5G mobile communication system). Asshown, in some embodiments, in order to support virtualization ofnetwork functions, more efficient resource management and scheduling,the gNB may be divided into a central unit (gNB-CU) 30 and distributedunits (gNB-DUs) 40, where a standardized public interface F1 issupported between the central unit and the distributed unit. It shouldbe understood that although two gNB-DUs are shown in the figure, gNBsmay include more or fewer gNB-DUs. For the sake of simplicity, in thefollowing, the central unit (gNB-CU) and the distributed unit (gNB-DU)of the gNB are also briefly referred to as CU and DU respectively. TheCU provides Service Data Adaptation Protocol (SDAP), Packet DataConvergence Protocol (PDCP) and Radio Resource Control (RRC). The DUprovides radio link control protocol (RLC), medium access control (MAC)and physical layer functions, among others.

It can be seen from FIG. 21 that a base station (gNB) in a 5G mobilecommunication system is no longer considered as a single functionalentity like a base station (eNB) in a conventional LTE, but is dividedinto two functional entities, a CU and a DU. These two entitiesimplement different functions. In a conventional LTE network, a basestation is generally considered as a functional entity, and interactionsamong all functions of this entity may be treated as its internalimplementations. However, in the 5G mobile communication system, aconventional base station is divided into different functional entities,such as CU and DUs. If the functions contained in the CU and DUs need tobe interacted with each other, they are required to do so via the F1interface. The CU will provide a Connection Mobility Control (CMC)function. The Connection Mobility Control involves management of radioresources in either idle or mobile states, such as setting and/oradjusting of connection mobility parameters. Examples of the connectionmobility parameters are parameters such as cell selection/reselectionrelated parameters, cell handover related parameters, and the like. Inorder to implement the setting and/or adjusting of the connectionmobility parameters, the RRC function in the CU is required to generatesetting values and/or adjustment values of these connection mobilityparameters, and transmit them to other underlying protocol layers (e.g.the PDCP layer, the RLC layer, the MAC layer and the physical layer) toinform the UE. In order to implement the setting and/or adjusting ofthese connection mobility parameters, it is necessary to refer to thefollowing information, including but not limited to measurementinformation of the users downlink channel, measurement information of auplink channel, load information of a neighbor cell, distributioninformation of a data stream, transmission network (i.e. the linksconnecting different functional entities, including but not limited to alink connecting a CU and a DU, a link connecting two CUs, a linkconnecting a CU and another gNB, etc.) and hardware resourceinformation, strategies of operators, and the like. For details of theinformation, reference may be made to the resource status reportinitialization process and the resource status update process cited inTS36.423v14.2.0(2017-03) (Section 8.3.6 and Section 8.3.7). However,only the DU knows some of the above information (e.g., uplink channelmeasurement information) that is required to be referred in the settingsand/or adjusting of the connection mobility parameters. The uplinkchannel measurement information may include, for example, one or more ofthe following signal measurements: a measurement of an uplink referencesignal, a measurement of an uplink data signal, a measurement of anuplink random access signal, and the like. Accordingly, a mechanism isneeded to allow the information known only to a DU to help a CU setand/or adjust the connection mobility parameters.

It should be understood that the terms “CMC related parameters” and“connection mobility parameters” may be used interchangeably herein. Theparameter setting can be considered as a special case of the parameteradjustments, so for the sake of brevity, the term “setting and/oradjusting of parameters” is also referred to for short as “parameteradjustment” below unless otherwise indicated explicitly.

Hereinafter, a 5G mobile communication system will be used as an exampleapplication environment, and many implementations according to thepresent disclosure are specifically described. Hereinafter, unlessotherwise indicated explicitly, a base station refers to a base stationgNB of a 5G mobile communication system including different functionalentities CUs and DUs. However, it will be understood by those skilled inthe art that the present disclosure is not limited to the gNB, and maybe applied to other base stations including different functionalentities. The present disclosure is not limited to the followingimplementations, but is applicable to more other wireless communicationsystems, for example, a mobile communication system after the 5G.

As described above, the connection mobility parameters in the presentdisclosure are mobility related parameters such as cellselection/reselection related parameters, cell handover relatedparameters, and the like. A cell selection/reselection related parameteris, for example, a cell selection or reselection threshold, and thelike. A cell handover related parameters is, for example, a thresholdfor triggering a handover preparation procedure for a specific neighborcell, and the like.

As described above, the uplink channel measurement information in thepresent disclosure may include, for example, one or more of thefollowing signal measurements: a measurement of an uplink referencesignal, a measurement of an uplink data signal, a measurement of anuplink random access signal, and the like.

In addition, in the present disclosure, the name of a message is onlyused by way of example and not of limitation, and may be replaced withanother name as long as the message can deliver the specifiedinformation.

FIG. 29 schematically shows a block diagram of a central unit of a basestation, gNB-CU 30, according to an embodiment of the presentdisclosure.

As shown, the CU 30 may include a transmitting module 31, a receivingmodule 32, and a processing module 33.

The transmitting module 31 may be configured to transmit a message to adistributed unit.

The receiving module 32 may be configured to receive a message from thedistributed unit.

The processing module 33 may be configured for an overall control of thecentral unit gNB-CU 30. In particular, the processing module 33 may beconfigured to generate a message to be transmitted, parse a receivedmessage, perform a connection mobility adjustment, and the like.

FIG. 30 schematically shows a block diagram of a distributed unit of abase station, gNB-DU 40, according to an embodiment of the presentdisclosure.

As shown, the DU 40 may include a transmitting module 41, a receivingmodule 42, and a processing module 43.

The transmitting module 41 may be configured to transmit a message tothe central unit.

The receiving module 42 may be configured to receive a message from thecentral unit. The processing module 43 may be configured for an overallcontrol of the distributed unit gNB-DU 40. In particular, the processingmodule 43 may be configured to generate a message to be transmitted,parse a received message, and the like.

It should be understood that the structure of the central unit and thedistributed unit of the base station shown above is merely exemplary andnot limitative. The transmitting module and the receiving module in thecentral unit or distributed unit may be separate modules or may beintegrated into a transceiver module. In addition, the central unitand/or the distributed unit may include more modules, for example, mayinclude modules available for the central unit or the distributed unitof the base station that may have been developed or will be developed inthe future, and the like.

The central unit 30 and the distributed unit 40 in FIGS. 10 and 11 maycooperate to perform the connection mobility adjustment. The specificoperations of the gNB-CU and the gNB-DU will be described in detailbelow with reference to various embodiments.

FIGS. 22A and 22B schematically illustrate a schematic diagram of afirst method for performing a connection mobility adjustment accordingto a first embodiment of the present disclosure. In this embodiment, agNB-CU initiates a resource status request to a gNB-DU. FIG. 22A shows asituation where the request succeeds or at least partially succeeds.FIG. 22B shows the failure of the request.

As shown in FIG. 22A, the method begins at step 301.

In step 301, the gNB-CU transmits a gNB-DU resource status requestmessage to the gNB-DU. The gNB-DU resource status request message maycontain a combination of one or more of the following:

-   -   Identification information of the gNB-DU.    -   Instruction information that the gNB-DU needs to report uplink        channel measurement information to the gNB-CU.    -   A list of cells to which the above information required to be        reported belongs. Information in this list indicates that the        gNB-CU requests the gNB-DU to report the above information for        the cells in this list.    -   Period information or trigger information for reporting the        above information.    -   If the above information, which is requested to be reported,        needs to be periodically reported by the gNB-DU, the request        message will contain the period information. In some        implementations, the period for reporting the above information        may be different for different cells, and thus the request        message will give different reporting period information for        different cells. In some other implementations, the foregoing        information for each cell may be reported at the same        periodicity, and then a common reporting period information will        be provided in the request message.    -   If the above information, which is requested to be reported,        needs to be triggered by the gNB-DU according to the occurrence        of a specific event, the request message will contain event        information that triggers the gNB-DU to report. For example,        examples of the above trigger event may be: the average of the        uplink channel measurement results being less than a first        threshold; the minimum value of the uplink channel measurement        results being less than a second threshold; the uplink channel        measurement result indicating that it is less than the third        threshold and greater than the fourth threshold, or the cell        load being changed, and the like. The setting of the trigger        event for each cell may be different or may be the same. Thus,        in some implementations, the trigger events may be set the same.        In some other implementations, different trigger thresholds for        the same trigger event may be set for different cells. In still        other implementations, different trigger events may be set for        different cells.    -   If some cells report periodically and some cells perform an        event-triggered report for the information requested to be        reported, the request message may contain a reporting period set        for the periodically reporting cell and a trigger event set for        the event-triggered reporting cell. The reporting period and the        trigger event may be set respectively in the corresponding        manner as described above.    -   Measurement identification information related to the uplink        channel measurement, such as the measurement identity assigned        by the gNB-CU corresponding to the report of the uplink channel        measurement.    -   Instruction information related to controlling the report of the        uplink channel measurement, such as starting the measurement,        stopping the measurement, and the like.

If the gNB-DU can make the measurement requested by the gNB-CU or atleast part of it, the method proceeds to step 302.

In step 302, the gNB-DU transmits a gNB-DU resource status responsemessage to the gNB-CU. The gNB-DU resource status response message maycontain a combination of one or more of the following:

-   -   Measurement identification information contained in the received        gNB-DU resource status request message.    -   Measurement identification information assigned by the gNB-DU        relating to this uplink channel measurement. This identification        information, together with the above measurement identification        information contained in the gNB-DU resource status request        message, may uniquely characterize the report of the uplink        channel measurement.    -   Some cells can make the measurements requested in the gNB-DU        resource status request message, while some cells cannot do so.        Thus, the gNB-DU may indicate in the gNB-DU resource status        response message a list of cells that can make the requested        measurement and reporting, and/or a list of cells that cannot        make the requested measurement and reporting. Preferably, in        case the list of cells that cannot make the requested        measurement and reporting is indicated in the gNB-DU resource        status response message, a reason that the requested measurement        and reporting cannot be made may also be indicated.

In step 303, the gNB-DU transmits a gNB-DU resource status updateMessage to the gNB-CU. If the gNB-DU is instructed, in the gNB-DUresource status request message, to periodically report, the gNB-DUreports according to the periodicity in the request message. If thegNB-DU is instructed, in the gNB-DU resource status request message, tomake an event-triggered report, the gNB-DU reports upon the triggerevent occurs. The resource status update message may contain one or moreof the following:

-   -   Cell ID, the identity of the cell to which the measured uplink        signal belongs.    -   User ID, the identity of the UE to which the measured uplink        signal belongs.    -   Measured signal strength of the uplink signal from the UE        indicated by the user ID, such as reference signal received        power (RSRP), received signal strength indicator (RSSI), signal        energy. The signal strength information may be an actual        measurement result or a quantized result (for example, 0 to 100,        0 means the minimum signal strength, and 100 means the maximum        signal strength)    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as reference signal received        quality (RSRQ). Similarly, the signal quality information may be        an actual measurement result or a quantized result (for example,        0 to 100, 0 means the worst signal quality, and 100 means the        best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the UEs in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the UEs. The measurement results may        be actual measurement results or quantized results (for example,        0-100, 0 means the minimum signal strength/the worst signal        quality, and 100 means the maximum signal strength/the best        signal quality).

It is easy to understand that the resource status update message needsto include a user ID when the resource status update message includesthe measured signal strength, signal quality and/or level of the uplinksignal from the UE indicated by the user ID. When the resource statusupdate message includes the measurement results indicating the signalstrengths/signal qualities of the uplink signals of all the UEs in thecell indicated by the Cell ID, the resource status update message maynot include user IDs.

In step 304, the gNB-CU performs a connection mobility parameteradjustment according to the obtained measurement result of the uplinksignal and other information. This step 304 may be performed by theprocessing module. The other information includes, but not limited to,measurement information of the users downlink channel, load informationof a neighbor cell, distribution information of a data stream,transmission network (i.e. the links connecting different functionalentities, containing but not limited to a link connecting a CU and a DU,a link connecting two CUs, a link connecting a CU and another gNB, etc.)and hardware resource information, strategies of operators, and thelike, to perform the connection mobility parameter adjustment.

FIG. 22B shows the situation when the gNB-DU cannot make the measurementrequested by the gNB-CU, which may result in a feedback of a failuremessage.

As shown, step 301 in FIG. 22B is the same as step 301 in FIG. 22A.

In step 301, the gNB-CU transmits a gNB-DU resource status requestmessage to the gNB-DU.

If the gNB-DU cannot make the measurement requested by the gNB-CU, themethod proceeds to step 302 a.

In step 302 a, the gNB-DU transmits a gNB-DU resource status failuremessage to the gNB-CU.

In some implementations, the gNB-DU resource status failure message maysimply indicate that the gNB-DU resource status request cannot beresponded to.

In other embodiments, the gNB-DU resource status failure message mayindicate more information, for example, may contain one or more of thefollowing:

-   -   Measurement identification information contained in the received        gNB-DU resource status request message.    -   Measurement identification information assigned by the gNB-DU        relating to this uplink channel measurement information. This        identification information, together with the above measurement        identification information contained in the gNB-DU resource        status request message, may uniquely characterize the report of        the uplink channel measurement.    -   For the measurement requested in the gNB-DU resource status        request message, the gNB-DU may indicate in the gNB-DU resource        status failure message a list of cells for which the requested        measurement and reporting cannot be made, and reasons thereof.

FIGS. 23A and 23B schematically show a schematic diagram of a secondmethod for performing a connection mobility adjustment according to asecond embodiment of the present disclosure. In this embodiment, theconnection mobility adjustment request is initiated by the gNB-CU. FIG.23A shows a situation where the adjustment request is accepted or atleast partially accepted. FIG. 23B shows a situation where theadjustment request fails.

As shown in FIG. 23A, the method begins at step 401.

In step 401, the gNB-CU transmits a gNB connection mobility adjustmentrequest message to the gNB-DU. The gNB connection mobility adjustmentrequest message may contain a combination of one or more of thefollowing:

-   -   Cell identification information

The cell identification information identifies a cell for which aconnection mobility parameter needs to be adjusted.

The cell identification information of the cell for which a connectionmobility parameter needs to be adjusted includes an identity of onecell. This cell may belong to the gNB-DU that receives the message, ormay belong to another gNB-DU.

The cell identification information of the cell for which a connectionmobility parameter needs to be adjusted may contain identities of two ormore cells. The two or more cells may belong to a same gNB-DU, todifferent gNB-DUs controlled by a same gNB-CU, or to different gNBs.

-   -   Adjustment suggestion information for the connection mobility        parameter.

The adjustment suggestion information for the connection mobilityparameter may be a suggestion for adjusting the connection mobilityparameters given by the gNB-CU for the cells corresponding to each pieceof the cell identification information mentioned above.

The adjustment suggestion information for the connection mobilityparameter may include at least one of the following:

Information about delaying or advancing cellselection/reselection/handover as suggested by the gNB-CU. For example,it may be, as suggested by the gNB-CU, an indication message aboutdelaying or advancing a handover by adjusting the mobility parameters.For example, if the information is a first value (e.g., 0), it indicatesthat the gNB-CU will delay a user handover of the cell by adjusting themobility parameters. Conversely, if the information is a second value(e.g., 1), it indicates that the gNB-CU will advance the user handoverof the cell by adjusting the mobility parameters.

A reference value suggested by the gNB-CU for connection mobilityparameter adjustment

-   -   A reference value range (which may be represented by a maximum        value and a minimum value of the range) suggested by the gNB-CU        for connection mobility parameter adjustment

In some implementations, the adjustment suggestion information for eachcell may be different. In some other implementations, the adjustmentsuggestion information for each cell may be the same. In still otherimplementations, the cells to be adjusted may be divided into multiplegroups. For example, the principles for the grouping may be as follows:the cells in the same group have the same reason for adjusting theconnection mobility parameters; the cells in the same group may affecteach other when adjusting the mobility parameters; and the like. In thecell grouping implementation, corresponding suggestion information maybe given for each cell in each group respectively, as shown in Table 1below.

TABLE 1 Group 1 Group 2 Group 3 Cell 1 Cell 2, Cell 3 Cell 4, Cell 5,Cell 6 An indication message A reference value for A reference valueabout delaying or the connection mobility range for the advancing ahandover parameter adjustment connection mobility suggested for Cell 2parameter adjustment A reference value for suggested for Cell 4 theconnection mobility A reference value parameter adjustment range for thesuggested for Cell 3 connection mobility parameter adjustment suggestedfor Cell 5 A reference value range for the connection mobility parameteradjustment suggested for Cell 6

Reasons for the Connection Mobility Parameter Adjustment.

The reason for the connection mobility parameter adjustment indicatesthe specific reason that the gNB-CU suggests the connection mobilityparameter adjustment, such as load balancing, handover optimization, andthe like. For example, if there are a plurality of cells or groups ofcells to adjust, reasons may be given respectively for each cell or eachgroup of cells.

In step 402, the gNB-DU replies to the gNB-CU with a gNB connectionmobility adjustment acknowledgement message. The gNB connection mobilityadjustment acknowledgement message acknowledges the gNB connectionmobility adjustment request message. The gNB-DU determines whether theadjustment suggestion information for the connection mobility parameter,which is proposed by the gNB-CU, is feasible according to the obtainedinformation (such as uplink channel quality information, downlinkchannel quality information, and the like), and notifies the gNB-CU ofthe determination result. The gNB connection mobility adjustmentacknowledgement message may contain one or more of the following:

-   -   Cell identities of cells corresponding to feasible suggestion        information;    -   Cell identities of cells corresponding to infeasible suggestion        information.

Alternatively, in some implementations, the gNB connection mobilityadjustment acknowledgement message may further include additionalinformation for cells corresponding to feasible suggestion information;and/or additional information for cells corresponding to infeasiblesuggestion information.

The additional information for cells corresponding to feasiblesuggestion information may include, for example, further adjustmentsuggestion information given by the gNB-DU.

-   -   If the adjustment suggestion information for the connection        mobility parameter of a cell given by the gNB-CU in step 401 is        a reference value range for the connection mobility parameter        adjustment, the acknowledgement message may contain a reference        value corresponding to the suggested connection mobility        parameter adjustment for the cell (this reference value is        within the suggested reference value range).

The additional information for cells corresponding to infeasiblesuggestion information may include, for example, at least one of thefollowing given by the gNB-CU:

-   -   New adjustment suggestion information for a connection mobility        parameter of the cell corresponding to the infeasible suggestion        information;    -   Uplink channel measurement information for the cells to be        adjusted which are included in the connection mobility        adjustment request message; and/or    -   Reasons that the suggestion is not accepted.

Specifically, there are many forms for the new adjustment suggestioninformation, which is given by the gNB-CU, for a connection mobilityparameter of the cells corresponding to the infeasible suggestioninformation.

If the adjustment suggestion information, which is given by the gNB-CUin step 401, for the connection mobility parameter of the cell isinformation for delaying or advancing a cellselection/reselection/handover, the acknowledgement message may containsuggestion information for the cell which is given by the gNB-DU, suchas a suggestion about keeping the information or parameter for delayingor advancing the cell selection/reselection/handover unchanged, or asuggestion about a reference value for the connection mobility parameteradjustment, or a suggestion about a reference value range for theconnection mobility parameter adjustment.

If the adjustment suggestion information, which is given by the gNB-CUin step 401, for the connection mobility parameter of the cell is areference value for the connection mobility parameter adjustment, theacknowledgement message may contain a reference value range for theparameter adjustment of the cell as suggested by the gNB-DU.

If the adjustment suggestion information, which is given by the gNB-CUin step 401, for the connection mobility parameter of the cell is areference value range for the connection mobility parameter adjustment,the acknowledgement message may contain a new reference value range or areference value for the parameter adjustment of the cell as suggested bythe gNB-DU.

Specifically, in some implementations, the gNB connection mobilityadjustment acknowledgement message includes uplink channel measurementinformation of the cell served by the gNB-DU and presented in therequest message in step 401, and may include one or more of thefollowing:

-   -   Cell ID, the identity of the cell to which the measured uplink        signal belongs    -   User ID, the identity of the UE to which the measured uplink        signal belongs    -   Measured signal strength of the uplink signal from the UE        indicated by the user ID, such as RSRP, RSSI, and signal energy.        The strength information may be an actual measurement result or        a quantized result (for example, 0 to 100, 0 means the minimum        signal strength, and 100 means the maximum signal strength).    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results of the signal strengths/signal qualities of        the uplink signals of all the UEs in the cell indicated by the        Cell ID, such as an average value of the measurement results for        all the UEs. The measurement results may be actual measurement        results or quantized results (for example, 0-100, 0 means the        minimum signal strength/the worst signal quality, and 100 means        the maximum signal strength/the best signal quality).

Specifically, in some implementations, the gNB connection mobilityadjustment acknowledgement message may include a reason that theadjustment suggestion, given by the gNB-CU in step 401, for theconnection mobility parameter of the cell is not accepted.

Then, in step 403, the gNB-CU performs a connection mobility parameteradjustment according to the received gNB connection mobility adjustmentacknowledgement. This step may be performed by the processing module.

FIG. 23B shows a situation where the adjustment fails. Step 401 in FIG.23B is the same as that in FIG. 23A.

In step 401, the gNB-CU transmits a gNB connection mobility adjustmentrequest message to the gNB-DU.

If the gNB-DU does not agree with the suggestion information for allcells given by the gNB-CU, it proceeds to step 402 a.

In step 402 a, the gNB-DU may reply to the gNB-CU with a gNB connectionmobility adjustment failure message.

In some implementations, the gNB connection mobility adjustment failuremessage may simply indicate that the gNB connection mobility adjustmentrequest cannot be responded to.

In some other embodiments, the gNB connection mobility adjustmentfailure message may indicate more information, which may contain, forexample, cell identifiers corresponding to infeasible suggestioninformation. Alternatively, in some implementations, the gNB connectionmobility adjustment failure message may further include additionalinformation for cells corresponding to infeasible suggestioninformation, for example, it may include at least one of the following:

-   -   New adjustment suggestion information for a connection mobility        parameter of the cell corresponding to the infeasible suggestion        information;    -   Uplink channel measurement information for the cells to be        adjusted which are included in the connection mobility        adjustment request message; and/or    -   Reasons for a parameter adjustment failure.

Specifically, there are many forms for the new adjustment suggestioninformation, which is given by the gNB-CU, for a connection mobilityparameter of the cell corresponding to the infeasible suggestioninformation.

If the adjustment suggestion information, which is given by the gNB-CUin step 401, for the connection mobility parameter of the cell isinformation for delaying or advancing a cellselection/reselection/handover, the acknowledgement message may containsuggestion information for the cell which is given by the gNB-DU, suchas a suggestion about keeping the information or parameter for delayingor advancing the cell selection/reselection/handover unchanged, or asuggestion about a reference value for the connection mobility parameteradjustment, or a suggestion about a reference value range for theconnection mobility parameter adjustment.

If the adjustment suggestion information, which is given by the gNB-CUin step 401, for the connection mobility parameter of the cell is areference value for the connection mobility parameter adjustment, theacknowledgement message may contain a reference value range for theparameter adjustment of the cell as suggested by the gNB-DU.

If the adjustment suggestion information, which is given by the gNB-CUin step 401, for the connection mobility parameter of the cell is areference value range for the connection mobility parameter adjustment,the acknowledgement message may contain a new reference value range or areference value for the parameter adjustment of the cell as suggested bythe gNB-DU.

Specifically, in some implementations, the gNB connection mobilityadjustment acknowledgement message includes uplink channel measurementinformation of the cell served by the gNB-DU and presented in therequest message in step 401, and may include one or more of thefollowing:

-   -   Cell ID, the identity of the cell to which the measured uplink        signal belongs    -   User ID, the identity of the UE to which the measured uplink        signal belongs    -   Measured signal strength of the uplink signal from the UE        indicated by the user ID, such as RSRP, RSSI, and signal energy.        The strength information may be an actual measurement result or        a quantized result (for example, 0 to 100, 0 means the minimum        signal strength, and 100 means the maximum signal strength).    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the UEs in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the UEs. The measurement results may        be actual measurement results or quantized results (for example,        0-100, 0 means the minimum signal strength/the worst signal        quality, and 100 means the maximum signal strength/the best        signal quality).

FIGS. 24A and 24B schematically show a schematic diagram of a thirdmethod for performing a connection mobility adjustment according to athird embodiment of the present disclosure. The method in thisembodiment is similar to the method in the last embodiment, except thatthe gNB-DU initiates the connection mobility adjustment. At first, thegNB-DU sends the gNB-CU a gNB connection mobility adjustment requiredmessage, and operations thereafter are similar to those in the method ofthe last embodiment. FIG. 24A shows a situation where the adjustmentrequest is accepted or at least partially accepted. FIG. 24B shows asituation where the adjustment request fails.

As shown in FIG. 24A, the method begins at step 501.

In step 501, the gNB-DU transmits a gNB connection mobility adjustmentrequired message to the gNB-CU. The gNB connection mobility adjustmentrequired message may contain one or more of the following:

-   -   Cell identification information of a cell for which a connection        mobility parameter needs to be adjusted;

The cell identification information may be an identity of one cell,identities of two cells, or identities of more than two cells.

Alternatively, the cell identification information may be divided intomultiple groups, and each group may contain identities of one or two ormore cells. For example, the principles for the grouping may be asfollows: the cells in the same group have the same reason for adjustingthe connection mobility parameters; the cells in the same group mayaffect each other when adjusting the mobility parameters; and the like.

-   -   Uplink channel measurement information of the cell served by the        gNB-DU and presented in the gNB connection mobility adjustment        required message

The information may include one or more of the following:

Cell ID, the identity of the cell to which the measured uplink signalbelongs

User ID, the identity of the user to which the measured uplink signalbelongs

Measured signal strength of the uplink signal from the UE indicated bythe user ID, such as RSRP, RSSI, and signal energy The strengthinformation may be an actual measurement result or a quantized result(for example, 0 to 100, 0 means the minimum signal strength, and 100means the maximum signal strength).

Measured signal quality of the uplink signal from the UE indicated bythe user ID, such as RSRQ. The signal quality information may be anactual measurement result or a quantized result (for example, 0 to 100,0 means the worst signal quality, and 100 means the best signalquality).

Measured level (e.g., intensity level or quality level) of the uplinksignal from the UE indicated by the user ID, such as low, medium andhigh. The above level decision depends on a specific implementation ofthe gNB-DU. For example, the level is “low” if the signal strength orquality of the uplink signal is lower than a fourth threshold, “high” ifhigher than a fifth threshold, and “medium” if between the fourth andthe fifth thresholds.

Measurement results of the signal strengths/signal qualities of theuplink signals of all the UEs in the cell indicated by the Cell ID, suchas an average value of the measurement results for all the UEs. Themeasurement results may be actual measurement results or quantizedresults (for example, 0-100, 0 means the minimum signal strength/theworst signal quality, and 100 means the maximum signal strength/the bestsignal quality).

-   -   The reason for the connection mobility parameter adjustment,        such as load balancing, handover optimization, and the like.        This reason information may be given respectively for each cell,        and may be given respectively for each group of cells if cells        is grouped.

The method then proceeds to step 502.

In step 502, the gNB-CU transmits a gNB connection mobility adjustmentmessage to the gNB-DU. The gNB connection mobility adjustment messagemay be considered as a special type of the gNB connection mobilityadjustment request message in the above embodiment. For each cellrepresented by the cell identities in step 501, the gNB connectionmobility adjustment message may contain a combination of one or more ofthe following:

-   -   Cell identification information

Particularly, the cell identification information herein may include apart or all of the cell identification information of the cell containedin the gNB connection mobility adjustment required message in step 501,for which the connection mobility parameter adjustment is needed.

-   -   Adjustment suggestion information for the connection mobility        parameter.

This is suggestion information for the mobility parameter adjustment,which is given by the gNB-CU for the cell corresponding to the abovecell identification information.

The adjustment suggestion information for the connection mobilityparameter may include at least one of the following:

Information about delaying or advancing cellselection/reselection/handover as suggested by the gNB-CU. For example,it may be, as suggested by the gNB-CU, an indication message aboutdelaying or advancing a handover by adjusting the mobility parameters.For example, if the information is a first value (e.g., 0), it indicatesthat the gNB-CU will delay a user handover of the cell by adjusting themobility parameters. Conversely, if the information is a second value(e.g., 1), it indicates that the gNB-CU will advance the user handoverof the cell by adjusting the mobility parameter.

-   -   A reference value suggested by the gNB-CU for connection        mobility parameter adjustment    -   A reference value range (which may be represented by a maximum        value and a minimum value of the range) suggested by the gNB-CU        for connection mobility parameter adjustment        Similar to the above embodiment, in some implementations, the        adjustment suggestion information for each cell may be        different. In some other implementations, the adjustment        suggestion information for each cell may be the same. In still        other implementations, the cells to be adjusted may be divided        into multiple groups. In the cell grouping implementation,        corresponding suggestion information may be given for each cell        in each group respectively.

In addition, for a cell that does not change the connection mobilityparameter, this can be implemented by containing only a cell identity instep 502 without any adjustment suggestion information, or by containingno corresponding cell identity.

In step 503, the gNB-DU transmits a gNB connection mobility adjustmentacknowledgement message to the gNB-CU. This acknowledgement message issimilar to the acknowledgement message in step 402 of the aboveembodiment. In this embodiment, the acknowledgement message may containone or more of the following:

-   -   Cell identities of cells corresponding to feasible suggestion        information in step 502    -   Alternatively, if the suggestion information is a reference        range for connection mobility parameter adjustment, it may also        contain a suggested reference value. In one embodiment, the        reference value is within a suggested reference value range for        parameter adjustment, while, in another embodiment, the        reference value may not be within the suggested reference value        range for parameter adjustment.        If only suggestion information for part of cells is feasible,        for cells with feasible information, the above information will        be contained in the message as described above, while, for        infeasible cells, the message further contains at least one of        the following messages:    -   Identities of infeasible cells    -   Suggestion information about infeasible cells    -   If the suggestion information in step 502 for the cell is        information for delaying or advancing a cell        selection/reselection/handover, the acknowledgement message may        contain suggestion information for the cell which is given by        the gNB-DU, such as a suggestion about keeping the information        or parameter for delaying or advancing the cell        selection/reselection/handover unchanged, or a suggestion about        a reference value for the connection mobility parameter        adjustment, or a suggestion about a reference value range for        the connection mobility parameter adjustment.    -   If the suggestion information in step 502 for the cell is a        reference value for the parameter adjustment, the message may        contain a suggested reference value range for the parameter        adjustment of the cell.    -   If the suggestion information in step 502 for the cell is a        reference value range for the parameter adjustment, the message        may contain a new suggested reference value range or a suggested        reference value for the parameter adjustment of the cell.    -   Uplink channel measurement information of the cell served by the        gNB-DU and corresponding to infeasible suggestion information in        step 502, which may include one or more of the following:        -   Cell ID, the identity of the cell to which the measured            uplink signal belongs        -   User ID, the identity of the user to which the measured            uplink signal belongs

Measured signal strength of the uplink signal from the UE indicated bythe user ID, such as RSRP, RSSI, and signal energy The strengthinformation may be an actual measurement result or a quantized result(for example, 0 to 100, 0 means the minimum signal strength, and 100means the maximum signal strength).

Measured signal quality of the uplink signal from the UE indicated bythe user ID, such as RSRQ. The signal quality information may be anactual measurement result or a quantized result (for example, 0 to 100,0 means the worst signal quality, and 100 means the best signalquality).

Measured level (e.g., intensity level or quality level) of the uplinksignal from the UE indicated by the user ID, such as low, medium andhigh. The above level decision depends on a specific implementation ofthe gNB-DU. For example, the level is “low” if the signal strength orquality of the uplink signal is lower than a fourth threshold, “high” ifhigher than a fifth threshold, and “medium” if between the fourth andthe fifth thresholds.

Measurement results indicating the signal strengths/signal qualities ofthe uplink signals of all the UEs in the cell indicated by the Cell ID,such as an average value of the measurement results for all the UEs. Themeasurement results may be actual measurement results or quantizedresults (for example, 0-100, 0 means the minimum signal strength/theworst signal quality, and 100 means the maximum signal strength/the bestsignal quality).

Reasons that the Suggestion is not Accepted.

Then, in step 504, the gNB-CU performs a connection mobility parameteradjustment according to the received gNB connection mobility adjustmentacknowledgement. This step may be performed by the processing module.

FIG. 24B shows a situation where the adjustment fails. Steps 501 and 502in FIG. 24B are the same as those in FIG. 24A.

In step 501, the gNB-DU transmits a gNB connection mobility adjustmentrequired message to the gNB-CU.

In step 502, the gNB-CU transmits a gNB connection mobility adjustmentmessage to the gNB-DU.

If the gNB-DU does not agree with all the suggestion information givenby the gNB-CU, the method proceeds to step 503 a. In step 503 a, thegNB-DU replies with a gNB connection mobility adjustment failuremessage.

For each cell where the suggestion information is infeasible, theadjustment failure message may contain one or more of the following:

-   -   Identities of infeasible cells    -   suggestion information about infeasible cells

If the suggestion information in step 502 for the cell is informationfor delaying or advancing a cell selection/reselection/handover, theacknowledgement message may contain suggestion information for the cellwhich is given by the gNB-DU, such as a suggestion about keeping theinformation or parameter for delaying or advancing the cellselection/reselection/handover unchanged, or a suggestion about areference value for the connection mobility parameter adjustment, or asuggestion about a reference value range for the connection mobilityparameter adjustment.

If the suggestion information in step 502 for the cell is a referencevalue for the parameter adjustment, the message may contain a suggestedreference value range for the parameter adjustment of the cell.

If the suggestion information in step 502 for the cell is a referencevalue range for the parameter adjustment, the message may contain a newsuggested reference value range or a suggested reference value for theparameter adjustment of the cell.

-   -   Uplink channel measurement information of the cell served by the        gNB-DU and presented in the gNB connection mobility adjustment        required message, which may include one or more of the        following:    -   Cell ID, the identity of the cell to which the measured uplink        signal belongs    -   User ID, the identity of the user to which the measured uplink        signal belongs    -   Measured signal strength of the uplink signal from the user        indicated by the user ID, such as RSRP, RSSI, and signal energy.        The strength information may be an actual measurement result or        a quantized result (for example, 0 to 100, 0 means the minimum        signal strength, and 100 means the maximum signal strength)    -   Measured signal quality of the uplink signal from the user        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality)    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the users in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the users. The measurement results        may be actual measurement results or quantized results (for        example, 0-100, 0 means the minimum signal strength, and 100        means the maximum signal strength)

Reasons for a Parameter Adjustment Failure.

FIGS. 25A and 25B schematically illustrate a schematic diagram of afourth method for performing a connection mobility adjustment accordingto a fourth embodiment of the present disclosure. In this embodiment,the connection mobility adjustment is initiated by the gNB-DU. FIG. 25Ashows a situation where the adjustment request is accepted or at leastpartially accepted. FIG. 25B shows a situation where the adjustmentrequest fails.

As shown in FIG. 25A, the method begins at step 601.

In step 601, the gNB-DU transmits a gNB connection mobility adjustmentrequest message to the gNB-CU, and the message may contain a combinationof one or more of the following:

-   -   Cell identification information

This identification information may be an identity of a cell which maybelong to the gNB-DU that sends the message, or may belong to anothergNB-DU.

This identification information may also contain identificationinformation of two or more cells where each cell may belong to a samegNB-DU, to different gNB-DUs controlled by a same gNB-CU, or todifferent gNBs.

-   -   A suggestion for adjusting the mobility parameters given by the        gNB-DU for each piece of the cell identification information,        which may be one of the following three pieces of suggestions        information:

Information about delaying or advancing cellselection/reselection/handover as suggested by the gNB-DU. For example,it may be, as suggested by the gNB-CU, an indication message aboutdelaying or advancing a handover by adjusting the mobility parameters.For example, if the information is a first value (e.g., 0), it indicatesthat the gNB-CU is suggested to delay a user handover of the cell byadjusting the mobility parameters. Conversely, if the information is asecond value (e.g., 1), it indicates that the gNB-CU is suggested toadvance the user handover of the cell by adjusting the mobilityparameter.

A reference value suggested by the gNB-DU for connection mobilityparameter adjustment

-   -   A reference value range (which may be represented by a maximum        value and a minimum value of the range) suggested by the gNB-DU        for connection mobility parameter adjustment

In some implementations, the adjustment suggestion information for eachcell may be different. In some other implementations, the adjustmentsuggestion information for each cell may be the same. In still otherimplementations, the cells to be adjusted may be divided into multiplegroups. For example, the principles for the grouping may be as follows:the cells in the same group have the same reason for adjusting theconnection mobility parameters; the cells in the same group may affecteach other when adjusting the mobility parameters; and the like. In thecell grouping implementation, corresponding suggestion information maybe given for each cell in each group respectively, as shown in Table 2below.

TABLE 2 Group 1 Group 2 Group 3 Cell 1 Cell 2, Cell 3 Cell 4, Cell 5,Cell 6 An indication message A reference value for A reference valueabout delaying or the connection mobility range for the advancing ahandover parameter adjustment connection mobility suggested for Cell 2parameter adjustment A reference value for suggested for Cell 4 theconnection mobility A reference value parameter adjustment range for thesuggested for Cell 3 connection mobility parameter adjustment suggestedfor Cell 5 A reference value range for the connection mobility parameteradjustment suggested for Cell 6

-   -   Uplink channel measurement information of the cell served by the        gNB-DU and presented in the request message, which may include        one or more of the following:        -   Cell ID, the identity of the cell to which the measured            uplink signal belongs        -   User ID, the identity of the UE to which the measured uplink            signal belongs        -   Measured signal strength of the uplink signal from the UE            indicated by the user ID, such as RSRP, RSSI, and signal            energy. The strength information may be an actual            measurement result or a quantized result (for example, 0 to            100, 0 means the minimum signal strength, and 100 means the            maximum signal strength).        -   Measured signal quality of the uplink signal from the UE            indicated by the user ID, such as RSRQ. The signal quality            information may be an actual measurement result or a            quantized result (for example, 0 to 100, 0 means the worst            signal quality, and 100 means the best signal quality).        -   Measured level (e.g., intensity level or quality level) of            the uplink signal from the UE indicated by the user ID, such            as low, medium and high. The above level decision depends on            a specific implementation of the gNB-DU. For example, the            level is “low” if the signal strength or quality of the            uplink signal is lower than a fourth threshold, “high” if            higher than a fifth threshold, and “medium” if between the            fourth and the fifth thresholds.        -   Measurement results indicating the signal strengths/signal            qualities of the uplink signals of all the UEs in the cell            indicated by the Cell ID, such as an average value of the            measurement results for all the UEs. The measurement results            may be actual measurement results or quantized results (for            example, 0-100, 0 means the minimum signal strength/the            worst signal quality, and 100 means the maximum signal            strength/the best signal quality).    -   Reasons that the gNB-DU suggests performing the connection        mobility parameter adjustment, such as load balancing, handover        optimization, and the like. If suggestions for a plurality of        cells or groups of cells are included, each cell or each group        of cells may be given a corresponding reason.

In step 602, the gNB-CU replies to the gNB-DU with a gNB connectionmobility adjustment acknowledgement message. The gNB-CU may reply to thegNB-DU whether suggestion information for each cell is feasibleaccording to the obtained information (such as uplink channel qualityinformation, downlink channel quality information, and the like), whichmay contain one or more of the following:

-   -   Cell identities of cells corresponding to feasible suggestion        information    -   Alternatively, if the suggested information is a reference value        range for parameter adjustment, the acknowledgement message may        also contain a suggested reference value corresponding to the        cell. In one embodiment, the reference value is within a        suggested reference value range for parameter adjustment, while,        in another embodiment, the reference value may not be within the        suggested reference value range for parameter adjustment.

If suggestion information for more than one cells is contained in step601 and only suggestion information for part of the cells is feasible,for cells with feasible information, the above information will becontained in the message as described above, while, for infeasiblecells, the message further contains at least one of the followingmessages:

-   -   Cell identities of cells corresponding to infeasible suggestion        information    -   Suggestion information for infeasible cells:

If the suggestion information in step 601 for the cell is an instructionmessage about delaying or advancing a handover, the message may containsuggestion information for the cell, such as a suggestion about keepingthe parameter for delaying or advancing the handover unchanged, or asuggestion about a reference value range for parameter adjustment, or asuggestion about a reference value for parameter adjustment

If the suggestion information in step 601 for the cell is a referencevalue for the parameter adjustment, the message may contain a suggestedreference value range for the parameter adjustment of the cell

If the suggestion information in step 601 for the cell is a referencevalue range for the parameter adjustment, the message may contain anidentity of the cell and a newly suggested reference value range or asuggested reference value for the parameter adjustment of the cell.

Reasons that the Suggestion is not Accepted.

Then, in step 603, the gNB-CU performs a connection mobility parameteradjustment.

It should be understood that the execution order of step 603 and step602 may be arbitrary, which is not limited to that shown in FIG. 25A.Step 603 may be performed before, after or in parallel with step 602.

In addition, step 602 is optional. In some implementations, step 602 maybe omitted.

FIG. 25B shows a situation where the adjustment fails. Step 601 in FIG.25B is the same as that in FIG. 25A.

In step 601, the gNB-DU transmits a gNB connection mobility adjustmentrequest message to the gNB-CU.

If the gNB-CU does not agree with all the suggestion information givenby the gNB-DU, the method proceeds to step 602 a.

In step 602 a, the gNB-CU may reply with a gNB connection mobilityadjustment failure message.

In some implementations, the gNB connection mobility adjustment failuremessage may simply indicate that the gNB connection mobility adjustmentrequest cannot be responded to.

In some other embodiments, the gNB connection mobility adjustmentfailure message may indicate more information. For each cell, theadjustment failure message may contain at least of the following:

-   -   Cell identities of cells corresponding to infeasible suggestion        information    -   Suggestion information for infeasible cells:

If the suggestion information in step 601 for the cell is an instructionmessage about delaying or advancing a handover, the message may containsuggestion information for the cell, such as a suggestion about keepingthe parameter for delaying or advancing the handover unchanged, or asuggestion about a reference value range for parameter adjustment, or asuggestion about a reference value for parameter adjustment

If the suggestion information in step 601 for the cell is a referencevalue for the parameter adjustment, the message may contain a suggestedreference value range for the parameter adjustment of the cell

If the suggestion information in step 601 for the cell is a referencevalue range for the parameter adjustment, the message may contain anidentity of the cell and a newly suggested reference value range or asuggested reference value for the parameter adjustment of the cell.

Reasons for a Parameter Adjustment Failure.

FIGS. 26A and 26B schematically illustrate a schematic diagram of afifth method for performing a connection mobility adjustment accordingto a fifth embodiment of the present disclosure; The method in thisembodiment is similar to the method in the last embodiment, except thatthe gNB-CU initiates the connection mobility adjustment. At first, thegNB-CU sends the gNB-DU a gNB connection mobility adjustment demandmessage, and operations thereafter are similar to those in the method ofthe above embodiment.

FIG. 26A shows a situation where the adjustment succeeds or at leastpartially succeeds FIG. 26B shows a situation where the adjustmentfails.

As shown in FIG. 26A, the method begins at step 701.

In step 701, the gNB-CU transmits a gNB connection mobility adjustmentrequired message to the gNB-DU, and the message may contain acombination of one or more of the following:

-   -   Cell identification information of a cell for which a connection        mobility parameter needs to be adjusted;

The identification information may be an identity of one cell,identities of two cells, or identities of more than two cells.

Alternatively, the cell identification information may be divided intomultiple groups, and each group may contain identities of one or two ormore cells. For example, the principles for the grouping may be asfollows: the cells in the same group have the same reason for adjustingthe connection mobility parameters; the cells in the same group mayaffect each other when adjusting the mobility parameters; and the like.

-   -   The reason for the connection mobility parameter adjustment,        such as load balancing, handover optimization, and the like.        This reason information may be given respectively for each cell.        Alternatively, this reason information may be given respectively        for each group of cells if cells is grouped.

In step 702, the gNB-CU transmits a gNB connection mobility adjustmentmessage to the gNB-DU. The gNB connection mobility adjustment messagemay be considered as a special type of the gNB connection mobilityadjustment request message. For each cell represented by the cellidentities contained in step 701, the message may contain a combinationof one or more of the following:

-   -   Cell identification information

Particularly, the cell identification information herein may include apart or all of the cell identification information of the cell containedin the gNB connection mobility adjustment required message in step 701,for which the connection mobility parameter adjustment is needed.

-   -   The suggestion information for the mobility parameter adjustment        given by the gNB-DU, which may be one of the following:        -   An indication message for delaying or advancing a handover            by adjusting the mobility parameters, or keeping the            handover parameter unchanged, as suggested by the gNB-DU.            For example, if the message is 0, it indicates that the            gNB-DU suggests delaying user handover of the cell indicated            by the cell identification information by adjusting the            mobility parameter; if the message is 1, it indicates            advancing the user handover of the cell; and if the message            is 2, it indicates keeping the parameter for cell handover            unchanged.        -   A reference value suggested by the gNB-DU for connection            mobility parameter adjustment

Reference value range for connection mobility parameter adjustment.

Similar to the above embodiment, in some implementations, the adjustmentsuggestion information for each cell may be different. In some otherimplementations, the adjustment suggestion information for each cell maybe the same. In still other implementations, the cells to be adjustedmay be divided into multiple groups. In the cell groupingimplementation, corresponding suggestion information may be given foreach cell in each group respectively.

In addition, for a cell that does not change the connection mobilityparameter, this can be implemented by including only a cell identity instep 702 without any adjustment suggestion information, or by includingno corresponding cell identity.

-   -   Uplink channel measurement information of the cell served by the        gNB-DU and presented in the gNB connection mobility adjustment        required message in step 701, which may include one or more of        the following:    -   Cell ID, the identity of the cell to which the measured uplink        signal belongs    -   User ID, the identity of the UE to which the measured uplink        signal belongs    -   Measured signal strength of the uplink signal from the UE        indicated by the user ID, such as RSRP, RSSI, and signal energy.        The strength information may be an actual measurement result or        a quantized result (for example, 0 to 100, 0 means the minimum        signal strength, and 100 means the maximum signal strength).    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the UEs in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the UEs. The measurement results may        be actual measurement results or quantized results (for example,        0-100, 0 means the minimum signal strength/the worst signal        quality, and 100 means the maximum signal strength/the best        signal quality).        In step 703, the gNB-CU transmits to the gNB-DU a gNB connection        mobility adjustment acknowledgement message. The acknowledgement        message may include one or more of the following:    -   Cell identities of cells corresponding to feasible suggestion        information in step 702    -   Alternatively, if the suggestion information is a reference        range for connection mobility parameter adjustment, it may also        contain a suggested reference value. In one embodiment, the        reference value is within a suggested reference value range for        parameter adjustment, while, in another embodiment, the        reference value may not be within the suggested reference value        range for parameter adjustment.

If only suggestion information for part of cells is feasible, for cellswith feasible information, the above information will be contained inthe message as described above, while, for infeasible cells, the messagefurther contains at least one of the following messages:

-   -   Identities of infeasible cells    -   Suggestion information about infeasible cells

If the suggestion information in step 702 for the cell is an instructionmessage about delaying or advancing a handover, the message may containsuggestion information for the cell, such as a suggestion about keepingthe parameter for delaying or advancing the handover unchanged, or asuggestion about a reference value range for parameter adjustment, or asuggestion about a reference value for parameter adjustment

If the suggestion information in step 702 for the cell is a referencevalue for the parameter adjustment, the message may contain a suggestedreference value range for the parameter adjustment of the cell

If the suggestion information in step 702 for the cell is a referencevalue range for the parameter adjustment, the message may contain a newsuggested reference value range or a suggested reference value for theparameter adjustment of the cell.

Reasons that the Suggestion is not Accepted.

Then, in step 704, the gNB-CU performs a connection mobility parameteradjustment. This step may be performed by the processing module.

It should be understood that the execution order of step 704 and step703 may be arbitrary, which is not limited to that shown in FIG. 26A.Step 704 may be performed before, after or in parallel with step 703.

In addition, step 703 is optional. In some implementations, step 703 maybe omitted.

FIG. 26B shows a situation where the adjustment fails. Steps 701 and 702in FIG. 26B are the same as those in FIG. 26A.

In step 701, the gNB-DU transmits a gNB connection mobility adjustmentrequest message to the gNB-CU.

In step 702, the gNB-CU transmits a gNB connection mobility adjustmentmessage to the gNB-DU.

If the gNB-CU does not agree with the suggestion information for all thecells given by the gNB-DU, the method proceeds to step 703 a. In step703 a, the gNB-CU may reply with a gNB connection mobility adjustmentfailure message. For each cell, the adjustment failure message maycontain one or more of the following:

-   -   Identities of infeasible cells    -   Suggestion information about infeasible cells

If the suggestion information in step 702 for the cell is an instructionmessage about delaying or advancing a handover, the message may containsuggestion information for the cell, such as a suggestion about keepingthe parameter for delaying or advancing the handover unchanged, or asuggestion about a reference value range for parameter adjustment, or asuggestion about a reference value for parameter adjustment

If the suggestion information in step 702 for the cell is a referencevalue for the parameter adjustment, the message may contain a suggestedreference value range for the parameter adjustment of the cell

If the suggestion information in step 702 for the cell is a referencevalue range for the parameter adjustment, the message may contain a newsuggested reference value range or a suggested reference value for theparameter adjustment of the cell.

-   -   Reasons for a Parameter Adjustment Failure.

FIG. 27 schematically illustrates a schematic diagram of a sixth methodfor performing a connection mobility adjustment according to a sixthembodiment of the present disclosure. In this embodiment, the connectionmobility adjustment is initiated by the gNB-CU.

As shown in FIG. 27, the method begins at step 801.

In step 801, the gNB-CU transmits a gNB connection mobility adjustmentrequest message to the gNB-DU. The message may contain a combination ofone or more of the following:

-   -   A cell identity for which a suggestion was provided        The cell represented by the above cell identity for which a        suggestion was provided will have associated suggestion        information

The identification information may be an identity of one cell. This cellmay belong to the gNB-DU that receives the message, or may belong toanother gNB-DU.

The identification information may also contain identificationinformation of two or more cells. The two or more cells may belong to asame gNB-DU, to different gNB-DUs controlled by a same gNB-CU, or todifferent gNBs.

-   -   A suggestion for adjusting the connection mobility parameters        given by the gNB-CU for each cell for which a suggestion was        provided, and the suggestion may be one of the following three        pieces of suggestions information:

Information about delaying or advancing cellselection/reselection/handover as suggested by the gNB-CU. For example,it may be, as suggested by the gNB-CU, an indication message aboutdelaying or advancing a handover by adjusting the mobility parameters.For example, if the information is a first value (e.g., 0), it indicatesthat the gNB-CU will delay a user handover of the cell by adjusting themobility parameters. Conversely, if the information is a second value(e.g., 1), it indicates that the gNB-CU will advance the user handoverof the cell by adjusting the mobility parameter.

A reference value suggested by the gNB-CU for connection mobilityparameter adjustment

A reference value range (which may be represented by a maximum value anda minimum value of the range) suggested by the gNB-CU for connectionmobility parameter adjustment

In some implementations, the adjustment suggestion information for eachcell may be different. In some other implementations, the adjustmentsuggestion information for each cell may be the same. In still otherimplementations, the cells to be adjusted may be divided into multiplegroups. For example, the principles for the grouping may be as follows:the cells in the same group have the same reason for adjusting theconnection mobility parameters; the cells in the same group may affecteach other when adjusting the mobility parameters; and the like. In thecell grouping implementation, corresponding suggestion information maybe given for each cell in each group respectively, as shown in Table 3below.

TABLE 3 Group 1 Group 2 Group 3 Cell 1 Cell 2, Cell 3 Cell 4, Cell 5,Cell 6 An indication message A reference value for A reference valueabout delaying or the connection mobility range for the advancing ahandover parameter adjustment connection mobility suggested for Cell 2parameter adjustment A reference value for suggested for Cell 4 theconnection mobility A reference value parameter adjustment range for thesuggested for Cell 3 connection mobility parameter adjustment suggestedfor Cell 5 A reference value range for the connection mobility parameteradjustment suggested for Cell 6

A Cell Identity for which a Suggestion is Expected:

The gNB-CU expects the gNB-DU to provide a suggestion regarding theconnection mobility parameter adjustment for the cell represented by theabove cell identity for which a suggestion is expected.

-   -   For each of the above cells, reasons that the gNB-DU suggests        performing the connection mobility parameter adjustment, such as        load balancing, handover optimization, and the like. If a        plurality of cells or groups of cells are included, each cell or        each group of cells may be given a corresponding reason.        In step 802, the gNB-DU replies to the gNB-CU with a gNB        connection mobility adjustment response message. The gNB-DU will        reply to the gNB-CU whether suggestion information provided in        step 801 is feasible according to the obtained information (such        as uplink channel quality information, downlink channel quality        information, and the like), which contains one or more of the        following:    -   Cell identities of cells corresponding to feasible suggestion        information    -   Alternatively, if the suggestion information given in step 801        for the cell is a reference value range for parameter        adjustment, the acknowledgement message may also contain a        suggested reference value corresponding to the cell. In one        embodiment, the reference value is within a suggested reference        value range for parameter adjustment, while, in another        embodiment, the reference value may not be within the suggested        reference value range for parameter adjustment. If suggestion        information for more than one cells is contained in step 801 and        only suggestion information for part of the cells is feasible,        then for cells with feasible information, the above information        will be contained in the message, while for infeasible cells,        the message further contains at least one of the following:    -   Cell identities of cells corresponding to infeasible suggestion        information    -   Alternatively, suggestion information for infeasible cells:

If the suggestion information in step 801 for the cell is an instructionmessage about delaying or advancing a handover, the message may containsuggestion information for the cell, such as a suggestion about keepingthe parameter for delaying or advancing the handover unchanged, or asuggestion about a reference value range for parameter adjustment, or asuggestion about a reference value for parameter adjustment

If the suggestion information in step 801 for the cell is a referencevalue for the parameter adjustment, the message may contain a suggestedreference value range for the parameter adjustment of the cell

If the suggestion information in step 801 for the cell is a referencevalue range for the parameter adjustment, the message may contain anidentity of the cell and a newly suggested reference value range or asuggested reference value for the parameter adjustment of the cell.

-   -   Alternatively, uplink channel measurement information of the        cell served by the gNB-DU and presented in the request message        in step 801, which may include one or more of the following:    -   Cell ID, the identity of the cell to which the measured uplink        signal belongs    -   User ID, the identity of the UE to which the measured uplink        signal belongs    -   Measured signal strength of the uplink signal from the UE        indicated by the user ID, such as RSRP, RSSI, and signal energy.        The strength information may be an actual measurement result or        a quantized result (for example, 0 to 100, 0 means the minimum        signal strength, and 100 means the maximum signal strength).    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the UEs in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the UEs. The measurement results may        be actual measurement results or quantized results (for example,        0-100, 0 means the minimum signal strength/the worst signal        quality, and 100 means the maximum signal strength/the best        signal quality).    -   Reasons that the Suggestion is not Accepted.

If the gNB-DU does not agree with all the suggestion information givenby the gNB-CU, for each cell for which a suggestion was provided in step801, the message may contain one or more of the following:

-   -   Cell identities of cells corresponding to infeasible suggestion        information    -   Alternatively, suggestion information for infeasible cells:    -   If the suggestion information in step 801 for the cell is an        instruction message about delaying or advancing a handover, the        message may contain suggestion information for the cell, such as        a suggestion about keeping the parameter for delaying or        advancing the handover unchanged, or a suggestion about a        reference value range for parameter adjustment, or a suggestion        about a reference value for parameter adjustment    -   If the suggestion information in step 801 for the cell is a        reference value for the parameter adjustment, the message may        contain a suggested reference value range for the parameter        adjustment    -   If the suggestion information in step 801 for the cell is a        reference value range for the parameter adjustment, the message        may contain a new suggested reference value range or a suggested        reference value for the parameter adjustment    -   Uplink channel measurement information of the cell served by the        gNB-DU and presented in the request message in step 801, which        may include one or more of the following:    -   Cell ID, the identity of the cell to which the measured uplink        signal belongs    -   User ID, the identity of the UE to which the measured uplink        signal belongs    -   Measured signal strength of the uplink signal from the UE        indicated by the user ID, such as RSRP, RSSI, and signal energy.        The strength information may be an actual measurement result or        a quantized result (for example, 0 to 100, 0 means the minimum        signal strength, and 100 means the maximum signal strength).    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the UEs in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the UEs. The measurement results may        be actual measurement results or quantized results (for example,        0-100, 0 means the minimum signal strength/the worst signal        quality, and 100 means the maximum signal strength/the best        signal quality).    -   Reasons for a Parameter Adjustment Failure.

If a cell identity for which a suggestion is expected is contained instep 801, for each such cell, the gNB-DU may give a suggestion foradjusting the connection mobility parameters, and/or may report uplinkchannel measurement information. Thus, for each cell for which asuggestion is expected, the message may contain one or more of thefollowing:

-   -   Suggestion information for the connection mobility parameter        adjustment, which may include at least one of the following:    -   Cell identification information    -   One of the following three suggestion information:    -   An indication message for delaying or advancing a handover by        adjusting the mobility parameters as suggested by the gNB-DU.        For example, if the message is 0, it indicates that the gNB-DU        will delay user handover of the cell by adjusting the mobility        parameter, or otherwise, if the message is 1, it indicates        advancing the user handover of the cell.    -   A reference value suggested by the gNB-DU for connection        mobility parameter adjustment    -   A reference value range (which may be represented by a maximum        value and a minimum value of the range) suggested by the gNB-DU        for connection mobility parameter adjustment    -   Uplink channel measurement information, which may include one or        more of the following:        -   Cell ID, the identity of the cell to which the measured            uplink signal belongs        -   User ID, the identity of the UE to which the measured uplink            signal belongs        -   Measured signal strength of the uplink signal from the UE            indicated by the user ID, such as RSRP, RSSI, and signal            energy. The strength information may be an actual            measurement result or a quantized result (for example, 0 to            100, 0 means the minimum signal strength, and 100 means the            maximum signal strength).    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the UEs in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the UEs. The measurement results may        be actual measurement results or quantized results (for example,        0-100, 0 means the minimum signal strength/the worst signal        quality, and 100 means the maximum signal strength/the best        signal quality).

In an optional step 803, the gNB-CU replies to the gNB-DU with a gNBconnection mobility adjustment acknowledgement message if suggestioninformation, for the cell for which a suggestion is expected in step801, is provided in step 802. For the cell, for which a suggestion isexpected, provided in each step 801 and the corresponding suggestioninformation provided in step 802, the following information may becontained:

-   -   Cell identities of cells for which the suggestion information        provided in step 802 is a feasible, among the cells for which a        suggestion is expected,    -   Alternatively, if the suggestion information is a reference        range for connection mobility parameter adjustment, it may also        contain a suggested reference value. In one embodiment, the        reference value is within a suggested reference value range for        parameter adjustment, while, in another embodiment, the        reference value may not be within the suggested reference value        range for parameter adjustment.

If only suggestion information for part of cells is feasible, for cellswith feasible information, the above information will be contained inthe adjustment acknowledgement message as described above, while, forinfeasible cells, the adjustment acknowledgement message furthercontains at least one of the following messages:

-   -   Identities of infeasible cells    -   Suggestion information about infeasible cells        -   If the suggestion information in step 802 for the cell is an            instruction message about delaying or advancing a handover,            the message may contain suggestion information for the cell,            such as a suggestion about keeping the parameter for            delaying or advancing the handover unchanged, or a            suggestion about a reference value range for parameter            adjustment, or a suggestion about a reference value for            parameter adjustment        -   If the suggestion information in step 802 for the cell is a            reference value for the parameter adjustment, the message            may contain a suggested reference value range for the            parameter adjustment of the cell        -   If the suggestion information in step 802 for the cell is a            reference value range for the parameter adjustment, the            message may contain a new suggested reference value range or            a suggested reference value for the parameter adjustment of            the cell.    -   Reasons that the Suggestion is not Accepted.

Additionally, if the gNB-CU does not agree with the suggestioninformation for all the cells given by the gNB-DU, for each cell, theadjustment acknowledgement message may contain one or more of thefollowing:

-   -   Identities of infeasible cells    -   Suggestion information about infeasible cells        -   If the suggestion information in step 802 for the cell is an            instruction message about delaying or advancing a handover,            the message may contain suggestion information for the cell,            such as a suggestion about keeping the parameter for            delaying or advancing the handover unchanged, or a            suggestion about a reference value range for parameter            adjustment, or a suggestion about a reference value for            parameter adjustment        -   If the suggestion information in step 802 for the cell is a            reference value for the parameter adjustment, the message            may contain a suggested reference value range for the            parameter adjustment of the cell        -   If the suggestion information in step 802 for the cell is a            reference value range for the parameter adjustment, the            message may contain a new suggested reference value range or            a suggested reference value for the parameter adjustment of            the cell.

Reasons for a Parameter Adjustment Failure.

Then, in step 804, the gNB-CU performs a connection mobility parameteradjustment. This step may be performed by the processing module.

It should be understood that the execution order of step 804 and step803 may be arbitrary, which is not limited to that shown in FIG. 27.Step 804 may be performed before, after or in parallel with step 803.

In addition, step 803 is optional. In some implementations, step 803 maybe omitted.

FIG. 28 schematically illustrates a schematic diagram of a seventhmethod for performing a connection mobility adjustment according to aseventh embodiment of the present disclosure; In this embodiment, theconnection mobility adjustment is initiated by the gNB-DU.

As shown in FIG. 28, the method begins at step 901.

In step 901, the gNB-DU transmits a gNB connection mobility adjustmentrequest message to the gNB-CU. The adjustment request message maycontain a combination of one or more of the following:

-   -   A cell identity for which a suggestion was provided

The cell represented by the above cell identity for which a suggestionwas provided will have associated suggestion information

-   -   This identification information may be an identity of a cell        which may belong to the gNB-DU that receives the message, or may        belong to another gNB-DU.    -   This identification information may also contain identification        information of two or more cells where the two or more cells may        belong to a same gNB-DU, to different gNB-DUs controlled by a        same gNB-CU, or to different gNBs.    -   A suggestion for adjusting the connection mobility parameters        given by the gNB-DU for each cell for which a suggestion was        provided, and the suggestion may be one of the following three        pieces of suggestions information:    -   An indication message for delaying or advancing a handover by        adjusting the mobility parameters as suggested by the gNB-DU.        For example, if the message is 0, it indicates that the gNB-CU        will delay user handover of the cell by adjusting the mobility        parameter, or otherwise, if the message is 1, it indicates        advancing the user handover of the cell.    -   A reference value suggested by the gNB-DU for connection        mobility parameter adjustment    -   A reference value range (which may be represented by a maximum        value and a minimum value of the range) suggested by the gNB-DU        for connection mobility parameter adjustment

In some implementations, the adjustment suggestion information for eachcell may be different. In some other implementations, the adjustmentsuggestion information for each cell may be the same. In still otherimplementations, the cells to be adjusted may be divided into multiplegroups. For example, the principles for the grouping may be as follows:the cells in the same group have the same reason for adjusting theconnection mobility parameters; the cells in the same group may affecteach other when adjusting the mobility parameters; and the like. In thecell grouping implementation, corresponding suggestion information maybe given for each cell in each group respectively, as shown in Table 4below.

TABLE 4 Group 1 Group 2 Group 3 Cell 1 Cell 2, Cell 3 Cell 4, Cell 5,Cell 6 An indication message A reference value for A reference valueabout delaying or the connection mobility range for the advancing ahandover parameter adjustment connection mobility suggested for Cell 2parameter adjustment A reference value for suggested for Cell 4 theconnection mobility A reference value parameter adjustment range for thesuggested for Cell 3 connection mobility parameter adjustment suggestedfor Cell 5 A reference value range for the connection mobility parameteradjustment suggested for Cell 6

A Cell Identity for which a Suggestion is Expected

The gNB-DU expects the gNB-CU to provide a suggestion regarding theconnection mobility parameter adjustment for the cell represented by theabove cell identity for which a suggestion is expected.

-   -   Alternatively, uplink channel measurement information of the        cell served by the gNB-DU and presented in the request message        in step 901, which may include one or more of the following:    -   Cell ID, the identity of the cell to which the measured uplink        signal belongs    -   User ID, the identity of the UE to which the measured uplink        signal belongs    -   Measured signal strength of the uplink signal from the UE        indicated by the user ID, such as RSRP, RSSI, and signal energy.        The strength information may be an actual measurement result or        a quantized result (for example, 0 to 100, 0 means the minimum        signal strength, and 100 means the maximum signal strength).    -   Measured signal quality of the uplink signal from the UE        indicated by the user ID, such as RSRQ. The signal quality        information may be an actual measurement result or a quantized        result (for example, 0 to 100, 0 means the worst signal quality,        and 100 means the best signal quality).    -   Measured level (e.g., intensity level or quality level) of the        uplink signal from the UE indicated by the user ID, such as low,        medium and high. The above level decision depends on a specific        implementation of the gNB-DU. For example, the level is “low” if        the signal strength or quality of the uplink signal is lower        than a fourth threshold, “high” if higher than a fifth        threshold, and “medium” if between the fourth and the fifth        thresholds.    -   Measurement results indicating the signal strengths/signal        qualities of the uplink signals of all the UEs in the cell        indicated by the Cell ID, such as an average value of the        measurement results for all the UEs. The measurement results may        be actual measurement results or quantized results (for example,        0-100, 0 means the minimum signal strength/the worst signal        quality, and 100 means the maximum signal strength/the best        signal quality).    -   For each above cell, reasons that the gNB-DU suggests performing        the connection mobility parameter adjustment, such as load        balancing, handover optimization, and the like. If a plurality        of cells or groups of cells are included, each cell or each        group of cells may be given a corresponding reason.

In step 902, the gNB-CU replies to the gNB-DU with a gNB connectionmobility adjustment response message. The gNB-CU will reply to thegNB-DU whether suggestion information provided in step 801 is feasibleaccording to the obtained information (such as uplink channel qualityinformation, downlink channel quality information, and the like), whichcontains one or more of the following:

-   -   Cell identities of cells corresponding to feasible suggestion        information    -   Alternatively, if the suggestion information given in step 901        for the cell is a reference value range for parameter        adjustment, the acknowledgement message may also contain a        suggested reference value corresponding to the cell. In one        embodiment, the reference value is within a suggested reference        value range for parameter adjustment, while, in another        embodiment, the reference value may not be within the suggested        reference value range for parameter adjustment.

If suggestion information for more than one cells is contained in step901 and only suggestion information for part of the cells is feasible,for cells with feasible information, the above information will becontained in the message, while, for infeasible cells, the messagefurther contains at least one of the following:

-   -   Cell identities of cells corresponding to infeasible suggestion        information    -   Alternatively, suggestion information for infeasible cells:        -   If the suggestion information in step 901 for the cell is an            instruction message about delaying or advancing a handover,            the message may contain suggestion information for the cell,            such as a suggestion about keeping the parameter for            delaying or advancing the handover unchanged, or a            suggestion about a reference value range for parameter            adjustment, or a suggestion about a reference value for            parameter adjustment        -   If the suggestion information in step 901 for the cell is a            reference value for the parameter adjustment, the message            may contain a suggested reference value range for the            parameter adjustment of the cell        -   If the suggestion information in step 901 for the cell is a            reference value range for the parameter adjustment, the            message may contain an identity of the cell and a newly            suggested reference value range or a suggested reference            value for the parameter adjustment of the cell.    -   Reasons that the Suggestion is not Accepted.

If the gNB-CU does not agree with all the suggestion information givenby the gNB-DU, for each cell for which a suggestion was provided in step901, the message may contain one or more of the following:

-   -   Cell identities of cells corresponding to infeasible suggestion        information    -   Alternatively, suggestion information for infeasible cells:        -   If the suggestion information in step 901 for the cell is an            instruction message about delaying or advancing a handover,            the message may contain suggestion information for the cell,            such as a suggestion about keeping the parameter for            delaying or advancing the handover unchanged, or a            suggestion about a reference value range for parameter            adjustment, or a suggestion about a reference value for            parameter adjustment        -   If the suggestion information in step 901 for the cell is a            reference value for the parameter adjustment, the message            may contain a suggested reference value range for the            parameter adjustment        -   If the suggestion information in step 901 for the cell is a            reference value range for the parameter adjustment, the            message may contain a new suggested reference value range or            a suggested reference value for the parameter adjustment    -   Reasons for a Parameter Adjustment Failure.

If a cell identity for which a suggestion is expected is contained instep 901, for each such cell, the gNB-CU may give a suggestion foradjusting the connection mobility parameters, which may contain thefollowing information:

-   -   Cell identification information    -   One of the following three suggestion information:    -   An indication message for delaying or advancing a handover by        adjusting the mobility parameters as suggested by the gNB-CU.        For example, if the message is 0, it indicates that the gNB-CU        will delay user handover of the cell by adjusting the mobility        parameter, or otherwise, if the message is 1, it indicates        advancing the user handover of the cell.    -   A reference value suggested by the gNB-CU for connection        mobility parameter adjustment    -   A reference value range (which may be represented by a maximum        value and a minimum value of the range) suggested by the gNB-CU        for connection mobility parameter adjustment

In optional step 903, the gNB-DU replies to the gNB-CU with a gNBconnection mobility adjustment acknowledgement message if suggestioninformation, for the cell for which a suggestion is expected in step901, is provided in step 902. For the cell, for which a suggestion isexpected, provided in each step 901 and the corresponding suggestioninformation provided in step 902, the following information iscontained:

-   -   Cell identities of cells for which the suggestion information        provided in step 902 is a feasible, among the cells for which a        suggestion is expected,    -   Alternatively, if the suggestion information is a reference        range for connection mobility parameter adjustment, it may also        contain a suggested reference value. In one embodiment, the        reference value is within a suggested reference value range for        parameter adjustment, while, in another embodiment, the        reference value may not be within the suggested reference value        range for parameter adjustment.

If only suggestion information for part of cells is feasible, for cellswith feasible information, the above information will be contained inthe message as described above, while, for infeasible cells, the messagefurther contains at least one of the following messages:

-   -   Identities of infeasible cells    -   Suggestion information about infeasible cells        -   If the suggestion information in step 902 for the cell is an            instruction message about delaying or advancing a handover,            the message may contain suggestion information for the cell,            such as a suggestion about keeping the parameter for            delaying or advancing the handover unchanged, or a            suggestion about a reference value range for parameter            adjustment, or a suggestion about a reference value for            parameter adjustment        -   If the suggestion information in step 902 for the cell is a            reference value for the parameter adjustment, the message            may contain a suggested reference value range for the            parameter adjustment of the cell        -   If the suggestion information in step 502 for the cell is a            reference value range for the parameter adjustment, the            message may contain a newly suggested reference value range            or a suggested reference value for the parameter adjustment            of the cell.    -   Alternatively, uplink channel measurement information of the        cell served by the gNB-DU and expecting a suggestion in step        901, which may include one or more of the following:        -   Cell ID, the identity of the cell to which the measured            uplink signal belongs        -   User ID, the identity of the UE to which the measured uplink            signal belongs        -   Measured signal strength of the uplink signal from the UE            indicated by the user ID, such as RSRP, RSSI, and signal            energy. The strength information may be an actual            measurement result or a quantized result (for example, 0 to            100, 0 means the minimum signal strength, and 100 means the            maximum signal strength).        -   Measured signal quality of the uplink signal from the UE            indicated by the user ID, such as RSRQ. The signal quality            information may be an actual measurement result or a            quantized result (for example, 0 to 100, 0 means the worst            signal quality, and 100 means the best signal quality).        -   Measured level (e.g., intensity level or quality level) of            the uplink signal from the UE indicated by the user ID, such            as low, medium and high. The above level decision depends on            a specific implementation of the gNB-DU. For example, the            level is “low” if the signal strength or quality of the            uplink signal is lower than a fourth threshold, “high” if            higher than a fifth threshold, and “medium” if between the            fourth and the fifth thresholds.        -   Measurement results indicating the signal strengths/signal            qualities of the uplink signals of all the UEs in the cell            indicated by the Cell ID, such as an average value of the            measurement results for all the UEs. The measurement results            may be actual measurement results or quantized results (for            example, 0-100, 0 means the minimum signal strength/the            worst signal quality, and 100 means the maximum signal            strength/the best signal quality).

Reasons that the Suggestion is not Accepted.

Additionally, if the gNB-DU does not agree with the suggestioninformation for all the cells given by the gNB-CU, for each cell, themessage may contain one or more of the following:

-   -   Identities of infeasible cells    -   Suggestion information about infeasible cells        -   If the suggestion information in step 902 for the cell is an            instruction message about delaying or advancing a handover,            the message may contain suggestion information for the cell,            such as a suggestion about keeping the parameter for            delaying or advancing the handover unchanged, or a            suggestion about a reference value range for parameter            adjustment, or a suggestion about a reference value for            parameter adjustment        -   If the suggestion information in step 902 for the cell is a            reference value for the parameter adjustment, the message            may contain a suggested reference value range for the            parameter adjustment of the cell        -   If the suggestion information in step 902 for the cell is a            reference value range for the parameter adjustment, the            message may contain a new suggested reference value range or            a suggested reference value for the parameter adjustment of            the cell.    -   Alternatively, uplink channel measurement information of the        cell served by the gNB-DU and expecting a suggestion in step        901, which may include one or more of the following:        -   Cell ID, the identity of the cell to which the measured            uplink signal belongs        -   User ID, the identity of the UE to which the measured uplink            signal belongs        -   Measured signal strength of the uplink signal from the UE            indicated by the user ID, such as RSRP, RSSI, and signal            energy. The strength information may be an actual            measurement result or a quantized result (for example, 0 to            100, 0 means the minimum signal strength, and 100 means the            maximum signal strength).            -   Measured signal quality of the uplink signal from the UE                indicated by the user ID, such as RSRQ. The signal                quality information may be an actual measurement result                or a quantized result (for example, 0 to 100, 0 means                the worst signal quality, and 100 means the best signal                quality).            -   Measured level (e.g., intensity level or quality level)                of the uplink signal from the UE indicated by the user                ID, such as low, medium and high. The above level                decision depends on a specific implementation of the                gNB-DU. For example, the level is “low” if the signal                strength or quality of the uplink signal is lower than a                fourth threshold, “high” if higher than a fifth                threshold, and “medium” if between the fourth and the                fifth thresholds.            -   Measurement results indicating the signal                strengths/signal qualities of the uplink signals of all                the UEs in the cell indicated by the Cell ID, such as an                average value of the measurement results for all the                UEs. The measurement results may be actual measurement                results or quantized results (for example, 0-100, 0                means the minimum signal strength/the worst signal                quality, and 100 means the maximum signal strength/the                best signal quality).

Reasons for a Parameter Adjustment Failure.

Then, in step 904, the gNB-CU performs a connection mobility parameteradjustment according to the received gNB connection mobility adjustmentacknowledgement. This step may be performed by the processing module.

Examples referring to the exemplary embodiments will be described assupplementary notes below. The above exemplary embodiments andmodifications thereto may also be described in whole or in part as thefollowing supplementary notes. However, the present disclosure andmodifications thereto, which are exemplified in the foregoing exemplaryembodiments, are not limited to the following.

(Supplementary Note 1)

A method performed in a central unit of a base station, comprising:

transmitting a resource status request message to a distributed unit ofthe base station;receiving a resource status response message and a resource statusupdate message from the base station; and

performing a connection mobility adjustment according to the receivedresource status response message and resource status update message.

(Supplementary Note 2)

A central unit in a base station comprising:

a transmitting module configured to transmit a resource status requestmessage to a distributed unit of the base station; and

a receiving module configured to receive a resource status responsemessage and a resource status update message from the distributed unitof the base station; and

a processing module configured to perform a connection mobilityadjustment according to the received resource status response messageand resource status update message.

(Supplementary Note 3)

A method performed in a distributed unit of a base station, comprising:

receiving a resource status request message from a central unit of thebase station;

transmitting a resource status response message and a resource statusupdate message to the central unit of the base station.

(Supplementary Note 4)

A distributed unit in a base station comprising:

a receiving module configured to receive a resource status requestmessage from a central unit of the base station; and

a transmitting module configured to transmit a resource status responsemessage and a resource status update message to the central unit of thebase station.

(Supplementary Note 5)

The method or unit of any of Supplementary Notes 1-4, wherein theresource status request message comprises any of the following:

identification information of the distributed unit;

instruction information that uplink channel measurement information isrequired to be reported;

a list of cells to which the uplink channel measurement informationrequired to be reported belongs;

period information or trigger information for the report;

measurement identification information assigned by the central unit andrelating to the uplink channel measurement; and

instruction information related to controlling the report of the uplinkchannel measurement information.

(Supplementary Note 6)

The method or unit of any of Supplementary Notes 1-4, wherein theresource status response message comprises any of the following:

measurement identification information assigned by the central unit;

measurement identification information assigned by the distributed unit;

a list of cells that can be measured and reported;

a list of cells that cannot be measured and reported;

reasons that the cells cannot be measured and reported.

(Supplementary Note 7)

The method or unit of any of Supplementary Notes 1-4, wherein theresource status update message comprises any of the following:

the identity of the cell corresponding to the reported measurement;

the user identity corresponding to the reported measurement;

measured signal strength;

measured signal quality;

measured signal level; and

overall signal strength/signal quality of the cell.

(Supplementary Note 8)

A method performed in a central unit of a base station, comprising:

transmitting a connection mobility adjustment request message to adistributed unit of the base station;

receiving a connection mobility adjustment acknowledgement message fromthe distributed unit of the base station, and

performing a connection mobility adjustment according to the receivedconnection mobility adjustment acknowledgement message.

(Supplementary Note 9)

The method of Supplementary Note 8, further comprising:

receiving a connection mobility adjustment required message from thedistributed unit of the base station, wherein transmitting theconnection mobility adjustment request message to the distributed unitof the base station is made in response to the received connectionmobility adjustment required message.

(Supplementary Note 10)

The central unit of Supplementary Note 8, wherein the connectionmobility adjustment request message includes at least one of thefollowing:

cell identification information of a cell for which a connectionmobility parameter needs to be adjusted;

adjustment suggestion information for the connection mobility parameter;

a reason for connection mobility parameter adjustment.

(Supplementary Note 11)

The method of Supplementary Note 10, wherein the adjustment suggestioninformation for the connection mobility parameter comprises at least oneof the following:

Information about delaying or advancing cellselection/reselection/handover;

a reference value for the connection mobility parameter adjustment;

a reference value range for the connection mobility parameteradjustment.

(Supplementary Note 12)

The method of Supplementary Note 8, wherein the connection mobilityadjustment acknowledgement message comprises at least one of thefollowing:

information about cells corresponding to feasible adjustment suggestioninformation; and/or

information about cells corresponding to infeasible adjustmentsuggestion information.

(Supplementary Note 13)

A central unit in a base station comprising:

a transmitting module configured to transmit a connection mobilityadjustment request message to a distributed unit of the base station;

a receiving module configured to receive a connection mobilityadjustment acknowledgement message from the distributed unit of the basestation; and

a processing module configured to perform a connection mobilityadjustment according to the connection mobility adjustmentacknowledgement message.

(Supplementary Note 14)

The central unit of Supplementary Note 13, wherein:

the receiving module is further configured to receive a connectionmobility adjustment required message from the distributed unit of thebase station, and the transmitting module is further configured totransmit the connection mobility adjustment request message to thedistributed unit of the base station in response to the connectionmobility adjustment required message.

(Supplementary Note 15)

The central unit of Supplementary Note 13, wherein the connectionmobility adjustment request message includes at least one of thefollowing:

cell identification information of a cell for which a connectionmobility parameter needs to be adjusted;

adjustment suggestion information for the connection mobility parameter;

a reason for connection mobility parameter adjustment.

(Supplementary Note 16)

The central unit of Supplementary Note 15, wherein the adjustmentsuggestion information for the connection mobility parameter comprisesat least one of the following:

information about delaying or advancing cellselection/reselection/handover;

a reference value for the connection mobility parameter adjustment;and/or

a reference value range for the connection mobility parameteradjustment.

(Supplementary Note 17)

The method of Supplementary Note 13, wherein the connection mobilityadjustment acknowledgement message comprises at least one of thefollowing:

information about cells corresponding to feasible adjustment suggestioninformation; and/or

information about cells corresponding to infeasible adjustmentsuggestion information.

(Supplementary Note 18)

A method performed in a distributed unit of a base station, comprising:

receiving a connection mobility adjustment request message from acentral unit of the base station;

transmitting, in response to the received connection mobility adjustmentrequest message, a connection mobility adjustment acknowledgementmessage to the central unit of the base station.

(Supplementary Note 19)

The method of Supplementary Note 18, further comprising:

transmitting a connection mobility adjustment required message to thecentral unit of the base station;

wherein the connection mobility adjustment request message is a responsemessage to the connection mobility adjustment required message.

(Supplementary Note 20)

The method of Supplementary Note 18, wherein the connection mobilityadjustment request message includes at least one of the following:

cell identification information of a cell for which a connectionmobility parameter needs to be adjusted;

adjustment suggestion information for the connection mobility parameter;

a reason for connection mobility parameter adjustment.

(Supplementary Note 21)

The method of Supplementary Note 20, wherein the adjustment suggestioninformation for the connection mobility parameter comprises at least oneof the following:

information about delaying or advancing cellselection/reselection/handover;

a reference value for the connection mobility parameter adjustment;and/or

a reference value range for the connection mobility parameteradjustment.

(Supplementary Note 22)

The method of Supplementary Note 18, wherein the connection mobilityadjustment acknowledgement message comprises at least one of thefollowing:

information about cells corresponding to feasible adjustment suggestioninformation; and/or

information about cells corresponding to infeasible adjustmentsuggestion information.

(Supplementary Note 23)

A distributed unit in a base station comprising:

a receiving module, configured to receive a connection mobilityadjustment request message from a central unit of the base station; and

a transmitting module, configured to transmit, in response to thereceived connection mobility adjustment request message, a connectionmobility adjustment acknowledgement message to the central unit of thebase station.

(Supplementary Note 24)

The distributed unit of Supplementary Note 23, wherein:

the transmitting module is further configured to transmit a connectionmobility adjustment required message to the central unit of the basestation;

wherein the connection mobility adjustment request message is a responsemessage to the connection mobility adjustment required message.

(Supplementary Note 25)

The distributed unit of claim 23, wherein the connection mobilityadjustment request message includes at least one of the following:

cell identification information of a cell for which a connectionmobility parameter needs to be adjusted;

adjustment suggestion information for the connection mobility parameter;

a reason for connection mobility parameter adjustment.

(Supplementary Note 26)

The distributed unit of claim 25, wherein the adjustment suggestioninformation for the connection mobility parameter comprises at least oneof the following:

information about delaying or advancing cellselection/reselection/handover;

a reference value for the connection mobility parameter adjustment;and/or

a reference value range for the connection mobility parameteradjustment.

(Supplementary Note 27)

The distributed unit of claim 23, wherein the connection mobilityadjustment acknowledgement message comprises at least one of thefollowing:

information about cells corresponding to feasible adjustment suggestioninformation; and/or

information about cells corresponding to infeasible adjustmentsuggestion information.

(Supplementary Note 28)

A method performed in a central unit of a base station, comprising:

receiving a connection mobility adjustment request message from adistributed unit of the base station; and

performing a connection mobility adjustment according to the receivedconnection mobility adjustment request message.

(Supplementary Note 29)

The method of Supplementary Note 28, further comprising:

transmitting a connection mobility adjustment acknowledgement message toa distributed unit of the base station.

(Supplementary Note 30)

The method of Supplementary Note 28, further comprising:

transmitting a connection mobility adjustment required message to adistributed unit of the base station;

wherein the connection mobility adjustment request message is a responseto the connection mobility adjustment required message.

(Supplementary Note 31)

A central unit in a base station comprising:

a receiving module configured to receive a connection mobilityadjustment request message from a distributed unit of the base station;and

a processing module configured to perform a connection mobilityadjustment according to the received connection mobility adjustmentrequest message.

(Supplementary Note 32)

The central unit of Supplementary Note 31, wherein:

the transmitting module is further configured to transmit a connectionmobility adjustment acknowledgement message to a distributed unit of thebase station.

(Supplementary Note 33)

The central unit of Supplementary Note 31, wherein:

the transmitting module is further configured to transmit a connectionmobility adjustment required message to a distributed unit of the basestation.

wherein the connection mobility adjustment request message is a responseto the connection mobility adjustment required message.

(Supplementary Note 34)

A method performed in a distributed unit of a base station, comprising:

transmitting a connection mobility adjustment request message to acentral unit of the base station; and

receiving a connection mobility adjustment acknowledgement message fromthe central unit of the base station.

(Supplementary Note 35)

The method of Supplementary Note 34, further comprising:

receiving a connection mobility adjustment required message from acentral unit of the base station,

wherein transmitting the connection mobility adjustment request messageto the central unit of the base station is made in response to thereceived connection mobility adjustment required message.

(Supplementary Note 36)

A distributed unit in a base station comprising:

a transmitting module configured to transmit a connection mobilityadjustment request message to a central unit of the base station; and

a receiving module configured to receive a connection mobilityadjustment acknowledgement message from the central unit of the basestation.

(Supplementary Note 37)

The distributed unit of Supplementary Note 36, wherein:

the receiving module is further configured to receive a connectionmobility adjustment required message from a central unit of the basestation,

wherein transmitting the connection mobility adjustment request messageto the central unit of the base station is made in response to thereceived connection mobility adjustment required message.

(Supplementary Note 38)

A method performed in a central unit of a base station, comprising:

transmitting a connection mobility adjustment request message to adistributed unit of the base station;

receiving a connection mobility adjustment response message from adistributed unit of the base station; and

performing a connection mobility adjustment according to the receivedconnection mobility adjustment response message.

(Supplementary Note 39)

The method of Supplementary Note 38, further comprising:

transmitting a connection mobility adjustment acknowledgement message toa distributed unit of the base station.

(Supplementary Note 40)

The method of Supplementary Note 38 or 39, wherein the connectionmobility adjustment request message includes at least one of thefollowing:

a cell identity of the cell for which a suggestion is provided, and itscorresponding adjustment suggestion information for the connectionmobility parameter;

a cell identity for which a suggestion is expected a reason for theadjustment.

(Supplementary Note 41)

The method of Supplementary Note 38 or 39, wherein the connectionmobility adjustment response message includes at least one of thefollowing:

information about cells corresponding to feasible suggestioninformation;

information about cells corresponding to infeasible suggestioninformation.

(Supplementary Note 42)

A central unit in a base station configured to perform a method of anyof Supplementary Notes 38-41.

(Supplementary Note 43)

A method performed in a distributed unit of a base station, comprising:

receiving a connection mobility adjustment request message from acentral unit of the base station;

transmitting a connection mobility adjustment response message to thecentral unit of the base station.

(Supplementary Note 44)

The method of Supplementary Note 43, further comprising:

receiving a connection mobility adjustment acknowledgement message fromthe central unit of the base station.

(Supplementary Note 45)

The method of Supplementary Note 43 or 44, wherein the connectionmobility adjustment request message includes at least one of thefollowing:

a cell identity of the cell for which a suggestion is provided, and itscorresponding adjustment suggestion information for the connectionmobility parameter;

a cell identity for which a suggestion is expected;

a reason for the adjustment.

(Supplementary Note 46)

The method of Supplementary Note 43 or 44, wherein the connectionmobility adjustment response message includes at least one of thefollowing:

information about cells corresponding to feasible suggestioninformation;

information about cells corresponding to infeasible suggestioninformation.

(Supplementary Note 47)

A distributed unit in a base station configured to perform a method ofany of Supplementary Notes 43-46.

(Supplementary Note 48)

A method performed in a central unit of a base station, comprising:

receiving a connection mobility adjustment request message from adistributed unit of the base station;

transmitting a connection mobility adjustment response message to thecentral unit of the base station;

receiving a connection mobility adjustment acknowledgement message fromthe distributed unit of the base station, and performing a connectionmobility adjustment according to the received connection mobilityadjustment acknowledgement message.

(Supplementary Note 49)

The method of Supplementary Note 48, wherein the connection mobilityadjustment request message includes at least one of the following:

a cell identity of the cell for which a suggestion is provided, and itscorresponding adjustment suggestion information for the connectionmobility parameter;

a cell identity for which a suggestion is expected;

a reason for the adjustment.

(Supplementary Note 50)

The method of Supplementary Note 48, wherein the connection mobilityadjustment response message includes at least one of the following:

information about cells corresponding to feasible suggestioninformation;

information about cells corresponding to infeasible suggestioninformation.

(Supplementary Note 51)

A central unit in a base station configured to perform a method of anyof Supplementary Notes 48-50.

(Supplementary Note 52)

A method performed in a distributed unit of a base station, comprising:

transmitting a connection mobility adjustment request message to acentral unit of the base station;

receiving a connection mobility adjustment response message from acentral unit of the base station; and

transmitting a connection mobility adjustment acknowledgement message toa central unit of the base station.

(Supplementary Note 53)

The method of Supplementary Note 52, wherein the connection mobilityadjustment request message includes at least one of the following:

a cell identity of the cell for which a suggestion is provided, and itscorresponding adjustment suggestion information for the connectionmobility parameter;

a cell identity for which a suggestion is expected; and

a reason for the adjustment.

(Supplementary Note 54)

The method of Supplementary Note 52, wherein the connection mobilityadjustment response message includes at least one of the following:

information about cells corresponding to feasible suggestioninformation;

information about cells corresponding to infeasible suggestioninformation.

(Supplementary Note 55)

A distributed unit in a base station configured to perform a method ofany of Supplementary Notes 52-55.

The method and apparatus involved in the present application have beendescribed above in connection with the preferred embodiments. Accordingto the method for connection mobility control performed via the F1interface according to the present disclosure, accuracy of setting ofparameters such as cell selection/reselection and/or handover can beimproved, and issues such as user handover failure, Ping-pong handover,load imbalance between cells and the like due to improper setting ofthese parameters can be reduced.

It should be understood by those skilled in the art that computerprogram instructions can be used to realize each block in structurediagrams and/or block diagrams and/or flowcharts as well as acombination of blocks in the structure diagrams and/or block diagramsand/or flowcharts. It should be understood by those skilled in the artthat these computer program instructions can be provided to generalpurpose computers, special purpose computers or other processors ofprogrammable data processing means to be implemented, so that solutionsdesignated in a block or blocks of the structure diagrams and/or blockdiagrams and/or flowcharts are executed by computers or other processorsof programmable data processing means.

The modules in the devices of the present disclosure can be integratedtogether, or can be deployed separately. The modules can be integratedinto one module, or can be further split into multiple submodules.

It should be understood by those skilled in the art that the drawingsare merely schematic diagrams of one preferred embodiment, and themodules or flows in the drawings are not necessary for theimplementation of the present disclosure.

It should be understood by those skilled in the art that the modules inthe devices in the embodiments can be distributed in the devices in theembodiments according to the descriptions in the embodiments, or can belocated in one or more devices in the embodiments in accordance withcorresponding changes. The modules in the embodiments can be integratedinto one module, or can be further split into multiple submodules.

The serial number in the present disclosure is merely for descriptionand does not indicate the superiority of the embodiments.

The foregoing description merely shows several specific embodiments ofthe present disclosure, and the present disclosure is not limitedthereto. Any variation conceived by those skilled in the art shall fallinto the protection scope of the present disclosure.

It should be understood by those skilled in the art that the presentdisclosure involves devices for carrying out one or more of operationsas described in the present disclosure. Those devices may be speciallydesigned and manufactured as intended or may include known devices in ageneral-purpose computer. These devices have computer programs storedtherein, which are selectively activated or reconfigured. Such computerprograms may be stored in device (such as computer) readable media or inany type of media suitable for storing electronic instructions andrespectively coupled to a bus, the computer readable media include butare not limited to any type of disk (including floppy disks, hard disks,optical disks, CD-ROM and magneto optical disks), ROM (Read-OnlyMemory), RAM (Random Access Memory), EPROM (Erasable ProgrammableRead-Only Memory), EEPROM (Electrically Erasable Programmable Read-OnlyMemory), flash memories, magnetic cards or optical line cards. In otherwords, the readable media include any media storing or transmittinginformation in a device (for example, computer) readable form.

It can be understood for those skilled in the art that each block of thestructure charts and/or block diagrams and/or flowchart illustrations,and combinations of blocks in the structure charts and/or block diagramsand/or flowchart illustrations, may be implemented by computer programinstructions. It can be understood for those skilled in the art that thecomputer program instructions may also be supplied to a general-purposecomputer, a special-purpose computer or other processor capable ofprogramming a data processing method for implementation, so that schemesspecified in one or more block of the structure charts and/or blockdiagrams and/or flowchart illustrations are implemented by a computer orother processor capable of programming a data processing method.

It can be understood for those skilled in the art that variousoperations, methods, steps in a flow, measures and schemes that havebeen discussed in the present disclosure may be alternated, changed,combined or deleted. In addition, those with various operations,methods, steps in a flow, measures and schemes that have been discussedin the present disclosure may further be alternated, changed,rearranged, disintegrated, combined or deleted. In addition, in theprior art, those with various operations, methods, steps in a flow,measures and schemes that discussed by the present disclosure mayfurther be alternated, changed, rearranged, disintegrated, combined ordeleted.

1-56. (canceled)
 57. A central unit of a base station in a wirelesscommunication system, the central unit, comprising: a transceiver; andat least one processor coupled to the transceiver and configured to:transmit, to a distributed unit, a configuration instruction message ofa radio bearer comprising first configuration information of twodifferent tunnels on an interface between the central unit and thedistributed unit in order to support a packet data convergence protocol(PDCP) duplication function; receive a configuration response messagereturned by a network, wherein the configuration response messagecomprises second configuration information of the two different tunnelson the interface between the central unit and the distributed unit; andat least one of transmit or receive, to or from the distributed unit,respectively, a data packet of the radio bearer using the two differenttunnels.
 58. The central unit of claim 57, wherein the at least oneprocessor is further configured to, in case that the data packet of theradio bearer configured with the PDCP duplication function is downlinkdata, transmit the data packet of the radio bearer using one of the twodifferent tunnels and a duplication of the data packet of the radiobearer using the other of the two different tunnels.
 59. The centralunit of claim 57, wherein the at least one processor is furtherconfigured to, in case that the data packet of the radio bearerconfigured with the PDCP duplication function is uplink data, process,at a PDCP layer, the received data packet of the radio bearer configuredwith the PDCP duplication function to obtain a PDCP service data unit(SDU) of the radio bearer configured with the PDCP duplication function.60. The central unit of claim 57, wherein the configuration instructionmessage of the radio bearer further comprises activation information ofthe PDCP duplication function of the radio bearer.
 61. The central unitof claim 57, wherein the configuration instruction message of the radiobearer further comprises at least one of the following information:information indicating the support of the PDCP duplication function;part or all of configuration information of two radio link controlprotocol (RLC) entities corresponding to the radio bearer; at least oneof identifier information or configuration information of two logicchannels corresponding to the two RLC entities; information about acorrespondence between the two different tunnels on the interfacebetween the central unit and the distributed unit and the two RLCentities; and indication information for identifying a duplicated datapacket.
 62. The central unit of claim 57, wherein the firstconfiguration information includes address information for receiving ortransmitting, by the central unit, the data packet of the radio bearer;and wherein the second configuration information includes addressinformation for receiving or transmitting, on the distributed unit, thedata packet of the radio bearer supporting the PDCP duplicationfunction.
 63. A distributed unit of a base station in a wirelesscommunication system, the distributed unit comprising: a transceiver;and at least one processor coupled to the transceiver and configured to:receive a configuration instruction message of a radio bearer,transmitted by a central unit, comprising first configurationinformation of two different tunnels on an interface between the centralunit and the distributed unit in order to support a packet dataconvergence protocol (PDCP) duplication function; transmit, to thecentral unit, a configuration response message carrying secondconfiguration information of the two different tunnels on the interfacebetween the distributed unit and the central unit; and at least one ofreceive or transmit, from or to the central unit, respectively, a datapacket of the radio bearer using the two different channels.
 64. Thedistributed unit of claim 63, wherein the at least one processor isfurther configured to, in case that the data packet of the radio bearerconfigured with the PDCP duplication function is downlink data, receivethe data packet of the radio bearer using one of the two differenttunnels and a duplication of the data packet of the radio bearer usingthe other of the two different tunnels.
 65. The distributed unit ofclaim 63, wherein the at least one processor is further configured to,in case that the data packet of the radio bearer configured with thePDCP duplication function is uplink data, transmit, by the two differenttunnels on the interface between the distributed unit and the centralunit, two identical data packets of the radio bearer configured with thePDCP duplication function acquired from two different cells to thecentral unit, wherein the two identical data packets are obtained viaphysical layers of the cells, MAC layers, two different logic channelsand corresponding RLC entities thereof.
 66. The distributed unit ofclaim 63, wherein the first configuration information includes addressinformation for receiving or transmitting, by the central unit, the datapacket of the radio bearer; and wherein the second configurationinformation includes address information for receiving by a receivingsubunit or transmitting by the transmitting subunit the data packet ofthe radio bearer configured with the PDCP duplication function.
 67. Thedistributed unit of claim 63, wherein the configuration instructionmessage of the radio bearer further comprises activation information ofthe PDCP duplication function of the radio bearer, and wherein the atleast one processor is further configured to activate or deactivate thePDCP duplication function based on the activation information.
 68. Thedistributed unit of claim 63, wherein the configuration instructionmessage of the radio bearer further comprises at least one of thefollowing information: information indicating the support of the PDCPduplication function; part or all of configuration information of tworadio link control protocol (RLC) entities corresponding to the radiobearer; at least one of identifier information or configurationinformation of two logic channels corresponding to the two RLC entities;information about a correspondence between the two different tunnels onthe interface between the central unit and the distributed unit and thetwo RLC entities; and indication information for identifying aduplicated data packet.
 69. A method for operating a central unit of abase station in a wireless communication system, the method comprising:transmitting a configuration instruction message of a radio bearercomprising first configuration information of two different tunnels onan interface between the central unit and a distributed unit in order tosupport a packet data convergence protocol (PDCP) duplication functionto a distributed unit; receiving a configuration response messagereturned by a network, wherein the configuration response messagecomprises second configuration information of the two different tunnelson the interface between the central unit and the distributed unit; andat least one of transmitting or receiving, to or from the distributedunit, respectively, a data packet of the radio bearer using the twodifferent tunnels.
 70. The method of claim 69, wherein the transmittingthe data packet comprises, transmitting the data packet of the radiobearer using one of the two different tunnels and a duplication of thedata packet of the radio bearer using the other of the two differenttunnels.
 71. The method of claim 69, wherein the receiving the datapacket comprises, processing, at a PDCP layer, the received data packetof the radio bearer configured with the PDCP duplication function toobtain a PDCP service data unit (SDU) of the radio bearer configuredwith the PDCP duplication function.
 72. The method of claim 69, whereinthe configuration instruction message of the radio bearer furthercomprises at least one of the following information: informationindicating the support of the PDCP duplication function; part or all ofconfiguration information of two radio link control protocol (RLC)entities corresponding to the radio bearer; at least one of identifierinformation or configuration information of two logic channelscorresponding to the two RLC entities; information about acorrespondence between the two different tunnels on the interfacebetween the central unit and the distributed unit and the two RLCentities; and indication information for identifying a duplicated datapacket.
 73. The method of claim 69, wherein the configurationinstruction message of the radio bearer further comprises activationinformation of the PDCP duplication function of the radio bearer. 74.The method of claim 69, wherein the first configuration informationincludes address information for receiving or transmitting, by thecentral unit, the data packet of the radio bearer, and wherein thesecond configuration information includes address information forreceiving or transmitting, on the distributed unit, the data packet ofthe radio bearer supporting the PDCP duplication function.
 75. Themethod of claim 69, wherein the receiving the data packet comprises,receiving, by the two different tunnels on the interface between thecentral unit and the distributed unit, two identical data packets of theradio bearer configured with the PDCP duplication function acquired fromtwo different cells, wherein the two identical data packets are obtainedvia physical layers of the cells, MAC layers, two different logicchannels and corresponding RLC entities thereof.